case study how to survive a cholera epidemic

Case Study: How to Survive a Cholera Epidemic

Created by Shannan Muskopf for AP Biology | Google Doc

Part I –  It’s in the Water!

The villagers were not unfamiliar with the seasonal disease that would come with the rains, though most did not understand the underlying cause.  The symptoms were always the same, a quick onset of very watery diarrhea.  As much as a liter of water would be lost every hour and the person would become dehydrated, eyes sunken and unable to eat.  There was even a name for this specific type of diarrhea, “rice-water stool,” because it resembled water in which rice had been rinsed.  Children were the most vulnerable, and many would die each year from this dreaded disease:  cholera.

Out of desperation, many villagers would wear masks or avoid contact with the sick, but such efforts were often ineffective, they would still get sick.   This year was different, this year, a group of scientists from Europe arrived to help.   They told the villagers to give the sick people a mixture of water, sugar, and salt.  They investigated the communal well that was the main source of water.   

The villagers were surprised when the scientists poured some kind of a liquid into the well, which they said was medicine.  Some of the villagers were afraid and refused to drink the water, instead drawing from a nearby well, they even drained the original well that the foreigners had added the treatment.    The Europeans returned to find that the villagers were using water from other nearby untreated wells, so they also placed the chemical in those, and to other wells they poured a purple dye to discourage people from drinking the water there.  The villagers were forced to drink from the treated well.   

After a few days, people in the village stopped getting sick.  Did the chemical poured in the well did help stop the spread of the disease?     * Note: This case is fictional, but similar events did take place in India in 1926 (Hausler, 2006, pp. 84–85)

1.  Consider actions taken by a foreign entity on the village.   What ethical issues does imposing a treatment on the villagers without their consent raise?  What steps could they have taken that would have made the situation more acceptable?

2. When is it appropriate to force a “cure” on a population? Remember that in North America many cities put fluoride in the water to prevent tooth decay. 

What’s In the Water?

Cholera is caused by a bacteria:  Vibrio cholerae  is a comma-shaped bacteria with a single flagellum, and is classified as a gram negative.   It is typical of most prokaryotes structurally.   Not all V. cholerae cause disease, but the ones that do can cause serious diarrhea and vomiting hours after injection.   During infection, the bacteria colonize the small intestine and use their pili to attach to the host cells.   Not all those who get infected get sick, and some only suffer mild symptoms

3.  Label the bacterium  (pili, nucleoid, ribosomes, flagellum, cell membrane, cell wall)

4.  Read the description above which describes how CTX works.   Biologists often create models to help them understand processes that are difficult to visualize.  Create a model (sketch) showing how V. cholerae causes diarrhea.  The model should be detailed and can include annotations.  Your goal is to help someone else understand what is happening.

How Do You Treat the Infected?

Treatment of cholera involves replacing the lost fluids and ions. Health care professionals can use IV’s to administer fluids or encourage the patient to drink water mixed with glucose and salt.  Glucose can help provide energy for victims who have not been able to keep food down, and the salt will help cells restore their homeostasis.   

5.  Refresh your memory on the digestive system.  On the image, identify each of the following and place an X in the area that is associated with the symptoms of cholera. [ Stomach | Large Intestine, Small intestine (duodenum) | Small intestine (jejunum) | Appendix )  

Some people can be exposed to cholera and not become infected.  Differences in pathogenicity may be related to the cell membrane and channels that allow the movement of chloride and sodium ions.   Those with variations in those transport proteins may be resistant to the effects of the toxin.   In fact, a mutation in a gene that codes for a membrane transport protein (CFTR) is responsible for the genetic disease cystic fibrosis.    In humans, this disease causes mucus to build up in the lungs, making it difficult to breathe.   Some scientists suggest that the mutation persists in the population due to a phenomenon called “heterozygote advantage,”, where being a carrier of a disease gives you an advantage.   For example, heterozygotes for sickle cell disease are resistant to malaria, but do not suffer the effects of the disease. 

6.  If heterozygote advantage is occuring with CF, in which populations would you expect to see more individuals with the CF gene.  Why? 

7.  Suggest a way that the cholera toxin could be used as a therapy for those with CF? 

Part II – Was the Water Contaminated?

When the Europeans put a chemical in the well, what they were trying to do was to “infect” the cholera bacteria.   All living things in nature are preyed upon, and that includes bacteria.  In fact, bacteria have very tiny enemies called bacteriophages.   Phages are not technically alive, they don’t need energy and they can’t reproduce on their own.  They can invade a bacteria and hijack the cell to force it to produce more phages.  This infection is deadly to the bacteria.

A bacteriophage is composed o f genetic information (RNA or DNA) enclosed in a protein capsule. It is shaped like a moon lander and has three distinct regions. The head contains the genetic material surrounded by a protein coat called the capsid . The neck and helical sheath are also composed of proteins and serve as a conduit for injecting the genetic material into a bacterium – like a syringe.  Just below the head is the body of the virus which sits on a base plate and has leg-like extensions called tail fibers used for docking onto a bacteria. 

The proteins making up the base plate and tail fibers have a three dimensional shape that make each unique.  Phages are specific for the bacteria they infect because the proteins must fit receptors on the cell surface, like a lock and a key.   Attachment of the phage occurs when the proteins match the receptors on the cell surface.  Penetration occurs when the DNA of the phage enters the host cell. Once inside the cell, biosynthesis occurs, where the phage DNA replicates and the host cell produces proteins that will be used to build more phages.  In the last stages, the phage particles are assembled and then are released from the host bacterium, a process called lysis that destroys the host.   New phages can then go infect new hosts. 

8.  Use the underlined structures in the first paragraph  to label the bacteriophage.  Why are bacteriophages (and viruses) not considered to be living organisms?

9.  Annotate the image below to describe the steps of infection by a phage using the underlined words above and number them to indicate the correct order.

The cycle illustrated is called the lytic cycle because it results in the production of new viruses.  Sometimes viruses follow another path, called the lysogenic cycle .  In this case, the viral genome integrates into the host DNA but remains dormant.  Each time the cell divides, it carries with it that dormant piece of viral DNA.   At some point, the viral DNA will activate and the cell will switch to the lytic pathway and produce more phages.   The lysogenic cycle also occurs with human viruses.  For example, herpes can remain dormant in your skin and then become activated, producing a cold sore.   We don’t always understand the reasons for this activation, but it usually never fails that you will get a cold sore the day before pictures or prom.

10. Would the villagers need to drink repeatedly or only once from the treated wells to obtain a sufficient dose to serve as a cure? What is the basis of your answer?

11 . Should the villagers be concerned that this bacterial virus will be harmful to their own cells?    Why or why not? 

12.  Explain the difference between the lytic cycle and the lysogenic cycle.   What would be the effect on treatment if the bacteriophage that was poured into the wells adopted a lysogenic life cycle?

Part III – What About Antibiotics?

Phages were an interesting phenomenon that did not get as much attention due to the development of antibiotics.   Cholera became easily treatable with antibiotics and the idea of using phages to control infection lost favor.  Antibiotics work by damaging parts of the cell that humans don’t have, such as the cell wall.   Some bacteria are naturally resistant to antibiotics, which poses a problem for their long term use.   When antibiotics are used, those bacteria that are resistant are more likely to survive. They reproduce and create a new generation that is also resistant.  Over time, antibiotics lose their effectiveness.     The rise of antibiotic resistant strains of bacteria is a major concern for modern day scientists.

The graph shows the result of an experiment where the growth of a bacterial population was monitored over time. Growth was monitored by measuring the turbidity of the culture (the more turbid a culture, the more cells are present). At 1 hour, the bacteria were divided into 4 different flasks. The bacteria in each of these flasks were subjected to different treatment (see below), and the bacteria were incubated and their growth monitored.

14.  Use of antibiotics can shorten the course of the disease.   Patients can be given antibiotics orally in addition to rehydration protocols.   Patients may start to feel better after a day, but they should still take the antibiotics.  Why?

15.  Do you think cholera may become resistant to phages?  Why or Why not?  In your answer, consider the differences between phage therapy and antibiotics. 

An Infectious Cure - National Center for Case Study Teaching in Science . (2018). Sciencecases.lib.buffalo.edu . Retrieved 27 January 2018, from http://sciencecases.lib.buffalo.edu/cs/collection/detail.asp?case_id=608&id=608

Azimi, A. (2018). “ Cystic fibrotics could survive cholera, choleraics could survive cystic fibrosis” ; hypothesis that explores new horizons in treatment of cystic fibrosis . Retrieved 27 January 2018, from

Big Picture . (2018). Big Picture . Retrieved 27 January 2018, from https://bigpictureeducation.com/biology-behind-cholera

Cholera . (2018). En.wikipedia.org . Retrieved 27 January 2018, from https://en.wikipedia.org/wiki/Cholera

Jensen, M., Faruque, S., Mekalanos, J., & Levin, B. (2006). Modeling the role of bacteriophage in the control of cholera outbreaks. Proceedings Of The National Academy Of Sciences , 103 (12), 4652-4657. http://dx.doi.org/10.1073/pnas.0600166103

Rodman, D., & Zamudio, S. (1991). The cystic fibrosis heterozygote — Advantage in surviving cholera?. Medical Hypotheses , 36 (3), 253-258. http://dx.doi.org/10.1016/0306-9877(91)90144-n

Concepts Addressed

Virus Bacteriophage Bacteria

Cyclic AMP CTX (cholera toxin) Water Potential Osmosis Cell Membrane Pathogenicity Digestive System Lytic Lysogenic Genetic Material (DNA and RNA) Protein Capsule Transport Proteins Cystic Fibrosis Heterozygote Advantage Antibiotics

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Simulation-based assessment of cholera epidemic response: a case study of al-hudaydah, yemen.

1. Introduction

2. materials and methods, 2.1. cholera susceptible-infected-recovered/susceptible, 2.1.1. indirect infection, 2.1.2. asymptomatic reinforcing feedback loop (r), 2.1.3. bacteria shedding.

• bacteria shedding from symptomatic is 10^4, hence, normalized to 10 4 /10 6 = 0.01
• bacteria shedding from a mildly infected individual is 10 8 , hence, normalized to 10 8 /10 6 = 100
• bacteria shedding from a severely infected individual is 10^12, hence, normalized to 10 12 /10 6 = 1,000,000

2.1.4. Symptomatic Reinforcing Feedback Loops (R)

2.1.5. recovered balancing feedback loops (b), 2.1.6. immunity waning, 2.2. cholera response-intervention structure, 2.2.1. water, sanitation and hygiene interventions (wash), clean water provision, sewage treatment plant, latrine construction, 2.2.2. healthcare interventions, diarrhea treatment centre (dtc), oral rehydration corner (orc), vaccination, 2.2.3. surveillance system, 2.3. other model settings, 2.4. model validation, 2.4.1. comparison to historical data, 2.4.2. sensitivity test, 3. scenario analysis and discussion, bau-base-early response, supplementary materials, author contributions, institutional review board statement, informed consent statement, data availability statement, acknowledgments, conflicts of interest.

• Médecins Sans Frontières. Management of a Cholera Epidemic. 2018th ed. 2018. Available online: https://medicalguidelines.msf.org/viewport/CHOL/english/management-of-a-cholera-epidemic-23444438.html (accessed on 20 September 2022).
• World Health Organization. Guidelines for Cholera Control ; World Health Organization: Geneva, Switzerland, 1993; Available online: https://apps.who.int/iris/handle/10665/36837 (accessed on 20 September 2022).
• Federspiel, F.; Ali, M. The Cholera Outbreak in Yemen: Lessons Learned and Way Forward. BMC Public Health 2018 , 18 , 1338. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Harpring, R.; Maghsoudi, A.; Fikar, C.; Piotrowicz, W.D.; Heaslip, G. An Analysis of Compounding Factors of Epidemics in Complex Emergencies: A System Dynamics Approach. J. Humanit. Logist. Supply Chain Manag. 2021 , 11 , 198–226. [ Google Scholar ]
• Spiegel, P.; Ratnayake, R.; Hellman, N.; Lantagne, D.S.; Ververs, M.; Ngwa, M.; Wise, P.H. Cholera in Yemen: A Case Study of Epidemic Preparedness and Response ; Johns Hopkins Center for Humanitarian Health: Baltimore, MD, USA, 2018. [ Google Scholar ]
• Davis, W.; Narra, R.; Mintz, E.D. Cholera. Curr. Epidemiol. Rep. 2018 , 5 , 303–315. [ Google Scholar ] [ CrossRef ]
• World Health Organization. Cholera Situation in Yemen December 2020 [Infographic]. Available online: https://applications.emro.who.int/docs/WHOEMCSR314E-eng.pdf?ua=1 (accessed on 20 September 2022).
• Burki, T. Yemen’s Neglected Health and Humanitarian Crisis. Lancet 2016 , 387 , 734–735. [ Google Scholar ] [ CrossRef ]
• Qadri, F.; Islam, T.; Clemens, J.D. Cholera in Yemen—An Old Foe Rearing Its Ugly Head. N. Engl. J. Med. 2017 , 377 , 2005–2007. [ Google Scholar ] [ CrossRef ]
• Emergency Operation Center. Cholera Response Health Actors and Partner Activities. 2021. Available online: https://app.powerbi.com/view?r=eyJrIjoiNTY3YmU0NTItMmFjYy00OTUxLWI2NzEtOTU5N2Q0MDBjMjE5IiwidCI6ImI3ZTNlYmJjLTE2ZTctNGVmMi05NmE5LTVkODc4ZDg3MDM5ZCIsImMiOjl9 (accessed on 20 September 2022).
• United Nations Office for the Coordination of Humanitarian Affairs. Yemen: Cholera Outbreak Tracker Governorate Profiles. Available online: https://public.tableau.com/views/001CholeraYemenTracker/FacilityBaseline?%3Aembed=y&%3AshowVizHome=no&%3Adisplay_count=y&%3Adisplay_static_image=y#!%2Fpublish-confirm (accessed on 20 September 2022).
• UNICEF. UNICEF Yemen Humanitarian Situation Report. Available online: https://reliefweb.int/sites/reliefweb.int/files/resources/UNICEFYemenHumanitarianSituationReport-August2018.pdf (accessed on 20 September 2022).
• Al-Mekhlafi, H.M. Yemen in a Time of Cholera: Current Situation and Challenges. Am. J. Trop. Med. Hyg. 2018 , 98 , 1558–1562. [ Google Scholar ] [ CrossRef ] [ PubMed ] [ Green Version ]
• Bellizzi, S.; Pichierri, G.; Cegolon, L.; Panu Napodano, C.M.; Ali Maher, O. Coordination during Cholera Outbreak Response: Critical Insights from Yemen. Am. J. Trop. Med. Hyg. 2021 , 105 , 1155–1156. [ Google Scholar ] [ CrossRef ]
• Barciela, R.; Bilge, T.; Brown, K.; Champion Christophe, A.S.; Shields, M.; Ticehurst, H.; Jutla, A.; Usmani, M.; Colwell, R. Early Action for Cholera Project. Yemen Case Study ; Met Office: Exeter, UK, 2021. [ Google Scholar ]
• Pruyt, E. Small System Dynamics Models for Big Issues: Triple Jump towards Real-World Complexity ; TU Delft Library: Delft, The Netherlands, 2013. [ Google Scholar ]
• Fung, I.C.-H. Cholera Transmission Dynamic Models for Public Health Practitioners. Emerg. Themes Epidemiol. 2014 , 11 , 1. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Richardson, G.P. System Dynamics: Simulation for Policy Analysis from a Feedback Perspective. In Qualitative Simulation Modeling and Analysis ; Springer: Berlin/Heidelberg, Germany, 1991; pp. 144–169. [ Google Scholar ]
• Rocca, R. Complex Systems Modeling for Humanitarian Action: Methods and Opportunities ; United Nations Office for the Coordination of Humanitarian Affairs: Geneva, Switzerland, 2021. [ Google Scholar ]
• Diphtheria & Cholera Response. Available online: https://www.humanitarianresponse.info/sites/www.humanitarianresponse.info/files/documents/files/eoc_sitrep_25_yemen.pdf (accessed on 20 September 2022).
• Camacho, A.; Bouhenia, M.; Alyusfi, R.; Alkohlani, A.; Naji, M.A.M.; de Radiguès, X.; Abubakar, A.M.; Almoalmi, A.; Seguin, C.; Sagrado, M.J.; et al. Cholera Epidemic in Yemen, 2016–2018: An Analysis of Surveillance Data. Lancet Glob. Health 2018 , 6 , e680–e690. [ Google Scholar ] [ CrossRef ]
• Sterman, J. Business Dynamics. Systems Thinking and Modeling for a Complex World ; McGraw Hill Higher Education: Boston, MA, USA, 2000. [ Google Scholar ]
• Pruyt, E. Making System Dynamics Cool? Using Hot Testing & Teaching Cases. In Proceedings of the 27th International Conference of the System Dynamics Society. System Dynamics Society, Albuquerque, New Mexico, 26 July 2009. [ Google Scholar ]
• Mwasa, A.; Tchuenche, J.M. Mathematical Analysis of a Cholera Model with Public Health Interventions. Biosystems 2011 , 105 , 190–200. [ Google Scholar ] [ CrossRef ]
• Wolfe, M.; Kaur, M.; Yates, T.; Woodin, M.; Lantagne, D. A Systematic Review and Meta-Analysis of the Association between Water, Sanitation, and Hygiene Exposures and Cholera in Case-Control Studies. Am. J. Trop. Med. Hyg. 2018 , 99 , 534–545. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Okoh, A.I.; Sibanda, T.; Nongogo, V.; Adefisoye, M.; Olayemi, O.O.; Nontongana, N. Prevalence and Characterisation of Non-Cholerae Vibrio Spp. in Final Effluents of Wastewater Treatment Facilities in Two Districts of the Eastern Cape Province of South Africa: Implications for Public Health. Environ. Sci. Pollut. Res. 2015 , 22 , 2008–2017. [ Google Scholar ] [ CrossRef ] [ PubMed ] [ Green Version ]
• Ng, Q.X.; De Deyn, M.L.Z.Q.; Loke, W.; Yeo, W.S. Yemen’s Cholera Epidemic Is a One Health Issue. J. Prev. Med. Public Health 2020 , 53 , 289. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Grad, Y.H.; Miller, J.C.; Lipsitch, M. Cholera Modeling: Challenges to Quantitative Analysis and Predicting the Impact of Interventions. Epidemiology 2012 , 23 , 523–530. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Chao, D.L.; Longini, I.M., Jr.; Morris, J.G., Jr. Modeling Cholera Outbreaks. Curr. Top. Microbiol. Immunol. 2014 , 379 , 195–209. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Kaper, J.B.; Morris, J.G., Jr.; Levine, M.M. Cholera. Clin. Microbiol. Rev. 1995 , 8 , 48–86. [ Google Scholar ] [ CrossRef ]
• Leung, T.; Matrajt, L. Protection Afforded by Previous Vibrio Cholerae Infection against Subsequent Disease and Infection: A Review. PLoS Negl. Trop. Dis. 2021 , 15 , e0009383. [ Google Scholar ] [ CrossRef ]
• Nelson, E.J.; Harris, J.B.; Morris, J.G., Jr.; Calderwood, S.B.; Camilli, A. Cholera Transmission: The Host, Pathogen and Bacteriophage Dynamic. Nat. Rev. Microbiol. 2009 , 7 , 693–702. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Chao, D.L.; Halloran, M.E.; Longini, I.M. Vaccination Strategies for Epidemic Cholera in Haiti with Implications for the Developing World. Proc. Natl. Acad. Sci. USA 2011 , 108 , 7081–7085. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Global Task Force on Cholera Control. Roadmap 2030. Available online: https://www.gtfcc.org/about-gtfcc/roadmap-2030/ (accessed on 20 September 2022).
• Al-Gheethi, A.A.S.; Abdul-Monem, M.O.; Al-Zubeiry, A.H.S.; Efaq, A.N.; Shamar, A.M.; Al-Amery, R.M.A. Effectiveness of Selected Wastewater Treatment Plants in Yemen for Reduction of Faecal Indicators and Pathogenic Bacteria in Secondary Effluents and Sludge. Water Pract. Technol. 2014 , 9 , 293–306. [ Google Scholar ] [ CrossRef ]
• Miller Neilan, R.L.; Schaefer, E.; Gaff, H.; Fister, K.R.; Lenhart, S. Modeling Optimal Intervention Strategies for Cholera. Bull. Math. Biol. 2010 , 72 , 2004–2018. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Parker, L.A.; Rumunu, J.; Jamet, C.; Kenyi, Y.; Lino, R.L.; Wamala, J.F.; Mpairwe, A.M.; Ciglenecki, I.; Luquero, F.J.; Azman, A.S.; et al. Adapting to the Global Shortage of Cholera Vaccines: Targeted Single Dose Cholera Vaccine in Response to an Outbreak in South Sudan. Lancet Infect. Dis. 2017 , 17 , e123–e127. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• World Health Organization. Ending Cholera a Global Roadmap to 2030. In Ending Cholera a Global Roadmap to 2030 ; UNICEF: Yemen, Yemen, 2017; p. 32. [ Google Scholar ]
• LaRocque, R.; Harris, J.B. Cholera: Clinical Features, Diagnosis, Treatment, and Prevention. This Top. Available online: https://www.uptodate.com/contents/cholera-clinical-features-diagnosis-treatment-and-prevention (accessed on 20 September 2022).
• Barlas, Y. Formal Aspects of Model Validity and Validation in System Dynamics. Syst. Dyn. Rev. 1996 , 12 , 183–210. [ Google Scholar ] [ CrossRef ]
• Turner, B.L. Model Laboratories: A Quick-Start Guide for Design of Simulation Experiments for Dynamic Systems Models. Ecol. Modell. 2020 , 434 , 109246. [ Google Scholar ] [ CrossRef ]
• Tuite, A.R.; Tien, J.; Eisenberg, M.; Earn, D.J.; Ma, J.; Fisman, D.N. Cholera Epidemic in Haiti, 2010: Using a Transmission Model to Explain Spatial Spread of Disease and Identify Optimal Control Interventions. Ann. Intern. Med. 2011 , 154 , 593–601. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• Abu-Lohom, N.; Muzenda, D.; Mumssen, Y.U. A WASH Response to Yemen’s Cholera Outbreak. World Bank Blogs 2018. Available online: https://blogs.worldbank.org/water/wash-response-yemen-s-cholera-outbreak (accessed on 20 September 2022).
• Al-Gheethi, A.; Noman, E.; Jeremiah David, B.; Mohamed, R.; Abdullah, A.; Nagapan, S.; Hashim Mohd, A. A Review of Potential Factors Contributing to Epidemic Cholera in Yemen. J. Water Health 2018 , 16 , 667–680. [ Google Scholar ] [ CrossRef ]
• Centers for Disease Control and Prevention. Antibiotic Treatment. Available online: https://www.cdc.gov/cholera/treatment/antibiotic-treatment.html (accessed on 20 September 2022).
• International Organization for Migration. Task Force for Population Movement Yemen August 2018. 2021. Available online: https://displacement.iom.int/yemen (accessed on 20 September 2022).
• Ali, A. IDPs in Hudaydah: Where Aid, Protection Don’t Always Reach; 2021. Available online: https://sanaacenter.org/ypf/idps-in-hudaydah/ (accessed on 20 September 2022).
• McCrickard, L.; Massay, A.E.; Narra, R.; Mghamba, J.; Mohamed, A.A.; Kishimba, R.S.; Urio, L.J.; Rusibayamila, N.; Magembe, G.; Bakari, M.; et al. Cholera Mortality during Urban Epidemic, Dar Es Salaam, Tanzania, August 16, 2015–January 16, 2016. Emerg. Infect. Dis. J. 2017 , 23 , 13. [ Google Scholar ] [ CrossRef ] [ Green Version ]
• UNICEF. UNCEF Cholera Tookit 2013. Available online: https://sites.unicef.org/cholera/Cholera-Toolkit-2013.pdf (accessed on 20 September 2022).
• Ochoa, B.; Surawicz, C.M. Diarrheal Diseases–Acute and Chronic. Available online: https://gi.org/topics/diarrhea-acute-and-chronic/ (accessed on 20 September 2022).
• Michas, F. Number of Patients That Physicians in the U.S. Saw per Day from 2012 to 2018. 2020. Available online: https://www.statista.com/statistics/613959/us-physicans-patients-seen-per-day/ (accessed on 20 September 2022).
• Günther, I.; Niwagaba, C.B.; Lüthi, C.; Horst, A.; Mosler, H.-J.; Tumwebaze, I.K. When Is Shared Sanitation Improved Sanitation?-The Correlation between Number of Users and Toilet Hygiene. 2012. Available online: https://www.ircwash.org/resources/when-shared-sanitation-improved-sanitation-correlation-between-number-users-and-toilet (accessed on 22 September 2022).
• Worldbank. People Practicing Open Defecation, Urban (% of urban population)-Yemen, Rep. Available online: https://data.worldbank.org/indicator/SH.STA.ODFC.UR.ZS?locations=YE (accessed on 20 September 2022).
• Ministry of Electricity and Water. Environmental Impact Assessment. Available online: Chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://documents1.worldbank.org/curated/en/279131468335060537/pdf/E4940V60P0576020Box353756B01PUBLIC1.pdf (accessed on 20 September 2022).
• Pezzoli, L. Global Oral Cholera Vaccine Use, 2013–2018. Vaccine 2020 , 38 , A132–A140. [ Google Scholar ] [ CrossRef ]
• Durham, L.K.; Longini, I.M., Jr.; Halloran, M.E.; Clemens, J.D.; Azhar, N.; Rao, M. Estimation of Vaccine Efficacy in the Presence of Waning: Application to Cholera Vaccines. Am. J. Epidemiol. 1998 , 147 , 948–959. [ Google Scholar ] [ CrossRef ]
• Shim, E.; Galvani, A.P. Distinguishing Vaccine Efficacy and Effectiveness. Vaccine 2012 , 30 , 6700–6705. [ Google Scholar ] [ CrossRef ]

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Loo, P.S.; Aguiar, A.; Kopainsky, B. Simulation-Based Assessment of Cholera Epidemic Response: A Case Study of Al-Hudaydah, Yemen. Systems 2023 , 11 , 3. https://doi.org/10.3390/systems11010003

Loo PS, Aguiar A, Kopainsky B. Simulation-Based Assessment of Cholera Epidemic Response: A Case Study of Al-Hudaydah, Yemen. Systems . 2023; 11(1):3. https://doi.org/10.3390/systems11010003

Loo, Pei Shan, Anaely Aguiar, and Birgit Kopainsky. 2023. "Simulation-Based Assessment of Cholera Epidemic Response: A Case Study of Al-Hudaydah, Yemen" Systems 11, no. 1: 3. https://doi.org/10.3390/systems11010003

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Cholera outbreaks

Cholera is a bacterial infection that can cause severe diarrhoea and vomiting. The symptoms of cholera are:  

• large amounts of diarrhoea (which sometimes looks like rice water) 
• vomiting (which sometimes looks like rice water) 
• leg cramps  
• feeling weak.  

Severe diarrhoea can cause dehydration, which can lead to weakness and even death if not treated rapidly. Symptoms and signs of dehydration are thirst, weakness or fatigue, sunken eyes and decreased skin elasticity. 

Infants, young children, older people and people who are already sick are most at risk of getting severely ill if they get cholera. The most important things to reduce cholera deaths is for anyone with symptoms to drink oral rehydration solution as soon as they become ill, and to get to a health centre fast.  

You can catch cholera by:  

• drinking contaminated water; 
• eating contaminated food (e.g., food that is raw, poorly cooked, or that becomes contaminated with poo (faeces) during preparation or storage); 
• contact with the poo (faeces), vomit or things that have been contaminated with the poo or vomit of someone who has cholera; and  
• unprotected contact with the body of someone who has died from cholera.  

Cholera treatment is simple: using oral rehydration solution. This can be bought/obtained from health workers or even made at home by mixing 1 litre safe water, 6 teaspoons sugar and half a teaspoon of salt.

If someone has cholera, they should be given oral rehydration solution and then taken to a health facility, cholera treatment centre or oral rehydration point. 

People with more severe symptoms may need additional treatment, including intravenous rehydration and antibiotics. 

Cholera is a threat wherever safe water supplies, sanitation, food safety and hygiene are inadequate. Water, sanitation and hygiene facilities are often inadequate in overpopulated settings where there is overcrowding (like refugee/IDP camps or prisons).  

Working hand-in-hand with communities to identify risks and improve water and sanitation systems can have significant benefits.  

People living in high-risk areas can reduce their risk by practicing good hygiene and safe food preparation.  

• Cholera outbreaks can be prevented by making sure that communities have access to safe water and good sanitation.  
• Open defecation (not using toilets/latrines) is a major driver of cholera outbreaks. Providing communities with access to toilets/latrines can provide significant health benefits.  
• Latrines should be at a safe distance (20–30 metres) from drinking water sources.  
• People can reduce their risk by avoiding defecating in or near water. Dirty diapers should be placed in plastic bags before they are thrown away.  

You can reduce the risk for you and your loved ones by:

• drinking safe water (well-monitored piped water, disinfected with household water treatment chemicals, boiled, or bottled); 
• using safe water for washing and preparing food and for cooking; 
• cleaning your hands regularly using soap and safe water (or an alcohol-based hand rub if there is no visible dirt), especially before eating, cooking, after using the toilet/latrine or changing your child’s diaper; 
• cooking food thoroughly, keeping it covered, and eating immediately after cooking it; and  
• not going to the toilet or washing yourself, hands or clothes near where you get your drinking water.

There are several things you can do to make sure that your water is safe to drink at home. If it's well-monitored, water piped into your home is usually safe to drink.

If your water looks dirty or cloudy, physically remove pathogens by filtering your water using a water filter, clean cloth, paper towel or coffee filter. After filtering, you should still boil or disinfect your water.  

You can boil your water for at least one minute before drinking. After boiling, store drinking water safely in a clean, tightly sealed container to avoid recontamination. 

You can also disinfect your water to make it safe to drink. After filtering, use household water treatment chemicals following the manufacturer’s instructions. If household water chemicals are not available, add 3 to 5 drops of chlorine (such as 5–9% unscented household bleach) to one litre of water. Wait at least 30 minutes before using. 

You can also drink bottled water.

There is a vaccine available against cholera. It is called the oral cholera vaccine, or OCV. Being vaccinated with OCV reduces your chances of getting infected with cholera. Vaccination is a critical tool to stopping cholera, but access to safe water and sanitation is the most important thing to protect communities.  

OCV is safe and effective. Rare side effects include nausea, vomiting and mild gastrointestinal discomfort.  

The oral cholera vaccine can be given to children over one year and adults. It is safe for you to receive the oral cholera vaccine if you are pregnant.  

The cholera vaccine is an oral vaccine, meaning it needs to be swallowed. In a 2-dose schedule, the doses should be taken at least 2 weeks apart (and not more than 6 months apart). This provides you with protection for at least 3 years.

Stay calm. Keep hydrated using oral rehydration solution (available from health workers, shops or can be made at home mixing 1 litre water with 6 teaspoons sugar and half a teaspoon of salt) or other fluids (soup, juice, soda, coconut milk etc.). You need to drink enough to replace the fluids you are losing.

Seek medical care. Go to the nearest oral rehydration point, cholera treatment centre or health care facility as fast as possible.  

Prevent the person who is unwell from getting dehydrated. Give them oral rehydration solution (available from health workers, shops or can be made at home mixing 1 litre water with 6 teaspoons sugar and half a teaspoon of salt) or other fluids (soup, juice, soda, coconut milk etc.). You need to help them replace the fluid they are losing; encourage them to keep drinking even if they can’t keep it down.

Seek medical care. Take them to the nearest cholera treatment centre or health care facility as fast as possible.  

You should seek help immediately if the person is unable to take enough fluids due to vomiting, or if the diarrhoea is severe. Other reasons for emergency care are confusion or drowsiness, muscle cramps, weakness (unable to sit up by themselves) and dizziness. 

Oral rehydration solution can successfully treat 80% of patients. If someone is dehydrated, drinking water alone is not enough to help them recover. This is why using oral rehydration salts is important.  

ORS is solution prepared by mixing 1 sachet of oral rehydration salts in 1 litre of safe water.  Follow the instructions on the packet.

If you don’t have oral rehydration salt sachets, you can make the same solution by mixing:   

• half a teaspoon of salt  
• 6 teaspoons of sugar  
• 1 litre of safe drinking-water or lightly salted rice water. 

If you don’t have access to sachets or sugar and salt for the home-made solution, the most important thing is to keep the patient drinking anything and to seek care fast.  

The risk of you catching cholera when caring for a sick person is low if you take some basic measures to protect yourself: 

• Wash your hands thoroughly with soap and safe water after taking care, touching the clothes, or bedding of the sick person. 
• Wash the sick person’s bedding or clothing away from drinking-water sources. 

If the sick person is using the household or community toilet, make sure it is cleaned and disinfected thoroughly after each use. Don’t let the sick person prepare food. 

Mothers should continue to breastfeed infants and young children even if they have been diagnosed with cholera. 

Take care to avoid getting infected via the clothing and bedding of a sick person: 

• machine washing between 60–90 °C with household laundry detergent following by a complete drying cycle or drying in direct sunlight; or
• if machine washing is not available, immerse in a large container of water, stir for 10 minutes and scrub to remove dirt (taking care to avoid splashes). 
• immersing in boiling water for 5 minutes; or  
• immersing in water with a 0.2% solution of chlorine for at least 10 minutes then rinsing. To make 0.2% solution of chlorine: If you are starting with 4% liquid bleach, mix bleach to water with a ratio of 1 : 19.
• using a full cycle of a dryer machine; or
• hanging to dry in direct sunlight.   

In cholera treatment centres, health workers will help to make sure the patient remains hydrated using oral rehydration salts. If the patient is severely ill, he/she may be given antibiotics. Children may receive zinc tablets.

There is a very high risk of catching cholera from a dead body. This means it is important to take steps to reduce the risks to you and your loved ones.  

Take steps to reduce the risk of cholera spreading to yourself or others before and during the funeral. Hold the funeral and burial as quickly as possible (preferably within 24 hours after death). Work together as a community to identify alternatives to rituals where people touch or kiss the body.  

Trained health personnel should help you with the respectful and safe preparation of the body and burial process to prevent further spread of cholera. Handle the body as little as possible yourself.  

If working with a trained health personnel to prepare the body is not possible, protect yourself by:  

• touching the body as little as possible; 
• washing your hands thoroughly with soap and safe water after touching their body, clothes or bedding;  
• removing and washing/disinfecting/drying any bedding, towels or clothing that may have had contact with diarrhoea or with the body; and
• washing bedding or clothing away from drinking-water sources. 

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Open Access

Peer-reviewed

Research Article

How does handwashing behaviour change in response to a cholera outbreak? A qualitative case study in the Democratic Republic of the Congo

Roles Conceptualization, Data curation, Formal analysis, Funding acquisition, Investigation, Methodology, Writing – original draft

* E-mail: [email protected]

Affiliation Department of Disease Control, London School of Hygiene and Tropical Medicine, London, United Kingdom

Roles Investigation, Validation, Writing – review & editing

Affiliation Independent Consultant, Goma, Democratic Republic of the Congo

Roles Funding acquisition, Project administration, Validation, Writing – review & editing

Affiliation Action Contre la Faim, Paris, France

Roles Supervision, Writing – review & editing

Affiliation Geneva Centre of Humanitarian Studies, Université de Genève, Geneva, Switzerland

Roles Methodology, Supervision

• Sian White, 
• Anna C. Mutula, 
• Modeste M. Buroko, 
• Thomas Heath, 
• François K. Mazimwe, 
• Karl Blanchet, 
• Val Curtis, 
• Robert Dreibelbis

• Published: April 12, 2022
• https://doi.org/10.1371/journal.pone.0266849
• Peer Review
• Reader Comments

Handwashing with soap has the potential to curb cholera transmission. This research explores how populations experienced and responded to the 2017 cholera outbreak in the Democratic Republic of the Congo and how this affected their handwashing behaviour.

Cholera cases were identified through local cholera treatment centre records. Comparison individuals were recruited from the same neighbourhoods by identifying households with no recent confirmed or suspected cholera cases. Multiple qualitative methods were employed to understand hand hygiene practices and their determinants, including unstructured observations, interviews and focus group discussions. The data collection tools and analysis were informed by the Behaviour Centred Design Framework. Comparisons were made between the experiences and practices of people from case households and participants from comparison households.

Cholera was well understood by the population and viewed as a persistent and common health challenge. Handwashing with soap was generally observed to be rare during the outbreak despite self-reported increases in behaviour. Across case and comparison groups, individuals were unable to prioritise handwashing due to competing food-scarcity and livelihood challenges and there was little in the physical or social environments to cue handwashing or make it a convenient, rewarding or desirable to practice. The ability of people from case households to practice handwashing was further constrained by their exposure to cholera which in addition to illness, caused profound non-health impacts to household income, productivity, social status, and their sense of control.

Conclusions

Even though cholera outbreaks can cause disruptions to many determinants of behaviour, these shifts do not automatically facilitate an increase in preventative behaviours like handwashing with soap. Hygiene programmes targeting outbreaks within complex crises could be strengthened by acknowledging the emic experiences of the disease and adopting sustainable solutions which build upon local disease coping mechanisms.

Citation: White S, Mutula AC, Buroko MM, Heath T, Mazimwe FK, Blanchet K, et al. (2022) How does handwashing behaviour change in response to a cholera outbreak? A qualitative case study in the Democratic Republic of the Congo. PLoS ONE 17(4): e0266849. https://doi.org/10.1371/journal.pone.0266849

Editor: Alison Parker, Cranfield University, UNITED KINGDOM

Received: December 2, 2021; Accepted: March 28, 2022; Published: April 12, 2022

Copyright: © 2022 White et al. This is an open access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Data Availability: The supporting dataset for this work is available via Figshare at the following link at the following citation: White, Sian (2022): Interviews and group discussions with crisis and outbreak affected populations in the Democratic Republic of the Congo on handwashing determinants. figshare. Dataset. https://doi.org/10.6084/m9.figshare.19469270.v1 Please note that this includes transcripts in English of all interviews and focus group discussions which have been redacted to remove any identifiable information. Interested researchers may also contact the corresponding author or the Research Governance and Integrity Office at LSHTM: [email protected] to access additional data.

Funding: SW and TH recieved the funding from the United States Agency for International Development’s Bureau of Humanitarian Assistance (Grant number: AID-OFDA-G-16-00270). Donor website: https://www.usaid.gov/who-we-are/organization/bureaus/bureau-humanitarian-assistance The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Competing interests: The authors have declared that no competing interests exist.

Introduction

For centuries cholera has been a marker of social inequalities, affecting the most vulnerable members of society and commonly occurring amid social and economic upheaval or disaster [ 1 ]. Cholera cases remain underreported but it is estimated that there are 2.9 million cases and 91,000 deaths annually due to the disease [ 1 , 2 ]. In 2017 major outbreaks occurred in Yemen, the Democratic Republic of the Congo (DRC), Nigeria, Somalia and South Sudan leading to the highest global numbers of cases in history [ 3 ].

In the past, cholera was viewed as a waterborne disease, with environment-to-human transmission of vibrio cholera believed to be responsible for the majority of transmission [ 4 ]. However, recent spatiotemporal analyses of cholera outbreaks have demonstrated how cases cluster among close contacts [ 5 – 8 ]. This human-to-human transmission is heightened in dense living environments, and where water access is limited or intermittent, causing hygiene to be compromised [ 8 ].

Handwashing with soap is frequently recommended by international response agencies as a key household-level cholera prevention behaviour [ 9 ]. A recent meta-analysis of case control studies conducted during cholera outbreaks found that self-reported good hygiene practices and the availability of handwashing materials had the highest protective affect of any of the water, sanitation and hygiene (WASH) factors assessed [ 10 ]. Another broader review of cholera risk factors also found that handwashing had smaller but still protective effect against symptomatic cholera [ 8 ]. The authors acknowledged that the included studies used inconsistent measures of self-reported behaviour, likely to result in overestimates of actual handwashing behaviour [ 11 ].

Another review assessing the impact of water, sanitation and hygiene (WASH) interventions on cholera control found that handwashing promotion programmes during outbreaks generally had a positive affect but were limited by the behavioural and health outcomes they used (e.g. self-reported symptoms rather than laboratory confirmation). A more recent study in Bangladesh was able to overcome measurement limitations, and demonstrated that case-targeted interventions to promote handwashing and water treatment were successful in increasing behaviour which consequently reduced secondary transmission to household contacts by almost half [ 12 ]. However the majority of handwashing interventions during cholera outbreaks continue to focus only on health education [ 13 ]. This is problematic because knowledge of the health benefits of handwashing is unlikely to be sufficient to realise sustained behaviour change [ 14 , 15 ]. During outbreaks there is a tendency for both researchers and practitioners to overemphasise the effect of cognitive determinants such as health knowledge, risk perception and fear, rather than taking a more holistic view of the determinants that could influence handwashing behaviour [ 15 ]. Outbreaks may also cause theory-informed processes for designing behaviour change programmes to be compromised due to the perceived need to act right away, rather than consult and learn from populations [ 16 ].

There have been calls for more qualitative research into hygiene behaviour during cholera outbreaks and new, scalable approaches to doing community engagement to support preventative behaviours [ 1 , 17 , 18 ]. This research responds to these calls and draws on anthropology and behavioural science to understand how individuals and communities experience and respond to outbreaks and whether this affects their handwashing behaviour. We explore both the consequences of cholera on people’s lives and the determinants of handwashing behaviour during the 2017 cholera outbreak in the eastern part of DRC.

This study took place in South Kivu in the eastern part of the DRC at the height of the 2017 cholera outbreak (October and November). The region experiences both endemic and epidemic cholera and in 2017 the outbreak was the largest in recent decades with >53,000 reported cases and 1,145 deaths [ 19 ]. The research took place in a town on the shores of Lake Kivu (known to be an environmental reservoir for cholera) [ 20 , 21 ], which is home to about 200,000 people. The region was purposively selected because it was described as a cholera ‘hot spot’[ 19 ]. It also hosts a large number of internally displaced persons (IDPs) who have fled armed conflict in neighbouring villages. At the time of this research, the government provided IDPs with a small plot of land (~3m2) within one of two informal camps in the town. IDPs were responsible for constructing their own makeshift shelters from tarps and branches. In addition to these camp-like settings, some IDPs rented homes from permanent residents. Host community members typically lived in brick or compacted mud houses with corrugated iron roofs. Both IDPs and host community members typically worked in agriculture or as small-scale market vendors, although IDPs would typically earn less than host community members on a daily basis. Water and sanitation access in the region was poor. Pit latrines were common but often in poor condition and shared by many households, particularly in the informal camps. Water was considered scarce and was intermittent. IDPs and host communities had access to the same water sources which included tap stands and boreholes or water collection from rivers and lakes.

Multiple non-government organisations (NGOs) had worked in the region as part of sporadic emergency response initiatives oriented towards health and WASH. At the time of the research a temporary Cholera Treatment Centre (CTC) had been established by an NGO and was providing free care for cholera cases. Handwashing promotion was widespread and predominantly consisted of health education delivered by volunteer relais communautaires (health volunteers from the community) who were trained by NGOs. Health awareness sessions focuses on cholera transmission and prevention behaviours. Exposure to hygiene promotion was similar among IDPs and host communities, with the exception that those living further outside of the town in were exposed less frequently.

Research framework

This research used unstructured observations, in-depth interviews (IDIs) and focus group discussions (FGDs) to explore a range of behavioural determinants. We used the Behaviour Centred Design (BCD) framework [ 22 ] to develop a list of determinant categories and to refine appropriate methods for exploring each. BCD draws on evolutionary and environmental psychology to define critical domains of behaviour including cognitive processes, individual characteristics, the settings where behaviours take place and the broader physical, social and contextual environment. S1 Table defines the 16 BCD determinant categories that were assessed within this research in relation to handwashing. It indicates which methods were used to explore them and how these methods were developed. All of the methods aimed to identify contextual associational relationships within these broader determinant categories. The methodology adopted in this research replicated a process used in Iraq to understand how behaviour was affected during post-conflict displacement [ 23 ].

For the observation and IDIs participants were selected purposively based on their exposure to cholera. To do this we worked with health staff to identify cholera cases registered within the last three months. Using this sampling frame, we purposively selected for a diversity in age, gender, geography (rural or urban) type of residence (residing in a camp or residing in the community). Once case households had agreed to participate in the research, we also approached other households in the nearby vicinity to be part of the research. We sampled these ‘comparison households’ against the same criteria for diversity. Some households participated in more than one method. Sampling continued until a degree of saturation was met for each method. FGD participants were sampled purposively to be similar in terms of gender, geographical regions and type of residence.

Data collection methods

Unstructured observations..

Unstructured observations were designed to provide contextual detail about handwashing. Observations took place in eight case households and eight comparison households. Observations were for 2–3 hours, typically beginning at 6am and finishing when the participant had to depart for work. Observers wrote down all actions that that were done by all household members and the time actions took place. Observers paid attention to ‘critical times’ for handwashing which were defined as handwashing after using the toilet, or cleaning a child’s bottom, and before preparing food, eating food or feeding a child. Observers noted whether hands were washed at these critical times and whether soap was used.

In-depth interviews.

A total of 51 IDIs were completed, involving 24 people from case households and 27 people from comparison households. Seven of the participants who took part in the observation also took part in the IDIs. For case households, we selected the individual who had cholera if they were over 18 and well enough to participate. Alternatively, the person primarily responsible for caring for the case was selected. Participants of a similar age and gender were then invited to participate from neighbouring comparison households. A total of eight participatory activities were used within the IDIs to explore perceived hygiene challenges, the enabling environment, water use, roles, capabilities, routines, norms, social networks, and broader contextual determinants. See S2 Table for details on these activities.

Focus group discussions.

43 people participated in the FGDs. Four FGDs were conducted with women, two of which comprised women residing in the IDP camps and two which were with host community members. Three FGDs were conducted with men, two of which were with IDPs and one with host community members. Six participatory activities were included in FGDs to explore the prioritisation of hygiene challenges, perceived risk of cholera, attitudes towards people who had cholera, preferences related to infrastructure and soap, and motivations of behaviour. See S3 Table for descriptions of these activities.

Data collection.

The data was collected by four of the authors (SW, ACM, MMB, FKM). We were a team with mixed cultural backgrounds (British and Congolese). Two days of classroom-based training was provided on the research rationale and the methods. We then piloted the methods in a similar setting and adapted the tools as necessary. All IDIs and FGDs were conducted in Congolese Swahili and audio recorded. Observation notes were taken by hand. At the end of each day of data collection we reflected on our findings and captured this through written field notes [ 24 ].

Data management and analysis.

Preliminary data analysis was done concurrently with data collection. This allowed us make theoretical and methodological notes [ 25 ] and decide when we had reached a point of saturation. All audio recordings from IDIs and FGDs were transcribed and translated. Methods with semi-quantitative data such as ranked or scaled information were summarised in spreadsheets. Visual data such as drawings, photos and videos were descriptively summarised. All data and the field notes were imported into NVivo 12 software. The data analysis followed the process outlined by Braun and Clarke [ 26 ]. Data were classified according to whether the participant was from a case household or a comparison household. An initial top-down coding framework was applied based on the determinants of the BCD checklist. A second phase of coding was then conducted based on emergent themes. Coding was conducted by the first author and then theme summaries were validated by ACM, MMB, FKM and TH.

Ethics and consent.

Informed written consent was obtained from each participant. The research was approved by the ethics committees at the London School of Hygiene and Tropical Medicine (Submission ID: 13545) and the School of Public Health at the University of Kinshasa (Submission ID: ESP/CE/038/2017). Permission to undertake this work was given by the Departments of Health in North and South Kivu. Organisations working in the area were informed of our work and preliminary findings were shared immediately after data collection to enable utilisation within programmatic work. Further detail on research permissions and stakeholder engagement is provided in an Inclusivity Questionnaire in S4 Table .

Participant characteristics

In total 104 people took part in this research with 40% of these coming from households with one or more cholera cases in the last 3 months. A higher proportion of women were included in the sample, this purposive selection reflected the fact that women in this region were more involved with hygiene-related tasks and caregiving. Almost half of the participants were illiterate and average family size was 6.5 people. The linguistic diversity of participants and the high levels of internal displacement and people returning post-displacement (62% experiencing displacement) are reflective of decades of conflict in this region. Table 1 summarises the socio-demographic characteristics of the sample.

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https://doi.org/10.1371/journal.pone.0266849.t001

Handwashing behaviour.

Handwashing with soap (HWWS) and hand rinsing were uncommon at critical times (HWWS = 1%, hand rinsing = 11%) and there was no discernible difference between behaviour in case households and comparison households or between IDPs and host community hosueholds. When handwashing with soap did occur, it was typically performed following dirty household cleaning tasks (such as sweeping or cleaning the toilet). Hand rinsing was commonly practiced before eating and feeding children. While people knew that ash could be used as an alternative to soap, this practice was not seen during any of the observations.

Determinants of handwashing behaviour.

We identified a range of context specific determinants of handwashing behaviour across the 16 BCD categories (See S5 Table for full list of determinants and their association with handwashing behaviour). Some of the determinants assessed appeared to have no impact on handwashing behaviour including ethnicity, religion, education level, sociality, access to ash, descriptive norms, knowledge about key handwashing moments, and the motives of comfort and affiliation. Below we describe determinants that had a reported positive or negative influence on behaviour.

Knowledge . All participants were familiar with cholera, its symptoms (e.g. mentioning cholera-specific symptoms like ‘rice water’ stools), and recommended prevention behaviours. However, cholera was often used as a catch-all term to describe a range of diarrhoeal diseases. Handwashing knowledge was high with all participants able to list critical moments for handwashing and explain how handwashing can interrupt disease transmission. Participants attributed their familiarity with cholera and preventative behaviours such as handwashing to frequent exposure to hygiene promotion activities.

Physical environment and behavioural settings . Across the various settings within study site, there was little in the physical environment to enable or cue handwashing at key times. In discussions with participants, they would often differentiate between handwashing being easy to do as a behaviour, but difficult for them to practice because they lacked the products (soap) and infrastructure (water and handwashing facilities) which could facilitate it. Most research participants were agricultural labourers and spent the majority of their days outside the home. During this time people typically had no access to soap or water, preventing handwashing from taking place. Within the camp settings, NGOs had constructed simple bucket-style handwashing facilities and in some of the rural settings tippy-taps had been promoted. However almost all of these were non-functional at the time of our research. Participants also admitted that even when these facilities were functional, water, soap and ash were not readily available at the stations. In FGDs participants agreed it was important to have “somewhere special” for handwashing. They felt handwashing stations acted as a reminder to wash hands at key times and helped to inculcate good habits in children. However, the basic handwashing facilities promoted by NGOs were seen as being “poor designs, for poor people”. They tended to break easily and therefore failed to have a lasting impact on behaviour. Participants felt handwashing facilities should symbolise hygiene, rather than just facilitating handwashing:

“It is essential to have a beautiful , an attractive hand washing facility so one is at ease when washing hands … the hand washing facility has to be always kept clean so that it does not disgust , and a facility has to be respected by the whole family and everyone . ” (Male FGD participant)

Almost all participants reported that water scarcity was a major barrier to hand hygiene and a source of stress within their lives. In general, participants did not think handwashing consumed much water. However, water access and usage was carefully calculated and prioritised for other household tasks like bathing, cooking, laundry and dishes. While water was often sectioned out for different purposes within the home, but no families felt they could easily put water aside for handwashing. Observations indicated people used a range of water for handwashing including washing their hands directly in nearby lakes and rivers and re-using grey water (e.g. water from dishwashing or laundry).

Soap was a valued and scarce commodity. Overall, 62% of households had no soap of any kind available at the time of our visit. Among those who did have soap, it was typically kept on a high shelf in the bedroom and therefore not conveniently available for handwashing. No one reported buying soap just for the purpose of handwashing. Rather, soap was typically purchased when laundry needed to be done and then a small leftover section may be used for bathing and handwashing. While laundry soap was affordable it was not desirable for handwashing:

“You know , this [laundry soap] is not a soap we want to use because it can damage hands , but we just use it because of poverty . ” (Female FGD participant)

As with water, soap use within the household involved conscious trade-offs and decision-making between family members:

“Getting soap is not easy…In a house of nine children , you understand that a piece of soap will not be prioritized for hand washing . If we manage to afford the piece of soap for 100 Congolese Francs only once a week … How , and on what , can you use just a small piece of soap ? Will you use for laundry ? For bathing ? Or for hand washing ? Things become complicated . ” (Female FGD participant)

Participants explained that it was relatively common to ask neighbours for soap and water if needed but said people would laugh at you if you asked for these items for handwashing.

The social environment—norms, routines and social influence

Daily routines were unpredictable for most of the participants, with individuals searching for employment in the fields of others on a day-to-day basis. Daily routines were further complicated by intermittent water supplies and individuals could spend several hours per day searching for water they considered to be safe. Combined, these factors created time and financial pressure. The irregularity of routines, and the daily stressors that accompanied this, decreased the likelihood of handwashing habits forming. This was because there were few routine sequences of behaviour to cue handwashing and there was limited ability to make plans related to handwashing (e.g. to budget to have enough soap in the house).

Handwashing was seen as socially desirable and an injunctive norm. Hand hygiene norms were heightened by the outbreak, with participants estimating 65% of their community had increased their frequency of handwashing due to cholera concerns. Despite this, social sanctions or judgment related to not washing hands was low:

“I cannot judge people around me for not being clean because sometimes I am not clean too … I think only about 30% of people would judge me negatively [if they saw me not washing my hands] because people are not focused on hand washing behaviour; they can take it as normal that people sometimes forget to wash their hands . ” (Female IDI participant from a comparison household)

Participants explained that people easily forgave each other for not washing hands because of their difficult circumstances. Social support for handwashing was limited. Participants felt handwashing could be facilitated by family members reminding each other to wash hands at key times, but this rarely happened in practice. The importance of handwashing behaviour was consistently reinforced by NGOs and while some people felt the repetition of handwashing messages helped to remind people, others found it frustrating that these organisations were unable to realise changes to their broader circumstances which would allow them to practice handwashing more regularly.

In FGDs participants were asked about which motives were associated with handwashing. Motives of love, attractiveness and status (e.g. wealth, education and social respect) were thought to be strongly associated with handwashing:

“No one can fall in love with someone with dirty hands ! ” (Female FGD participant) “An attractive person is likely to remember to wash hands because she is used to looking nice , so , her hands have to look nice as well . ” (Female FGD participant) “Highly educated people are always clean because they do work with white papers and with clean things , and so they also have to have clean hands . And again , these educated people teach others; they cannot go in front , teaching others when they are unclean . They have to have clean hands so that people consider and respect them . ” (Male FGD participant)

Handwashing was less strongly associated with nurture and was not seen to be associated with affiliation (fitting in with a group). Participants explained that even ‘good parents’ are unable to mind their children and encourage handwashing behaviour because everyone has to work long hours outside the home. Others explained that relationships were typically built on shared interests and needs and so handwashing didn’t necessarily help a person to fit in. Participants in IDIs and FGDs agreed that if a person was hungry, poor or upset they would be unable to prioritise handwashing:

“Hygiene and good nutrition work together . Cleanliness cannot be visible in a house where food is absent . I can’t think about handwashing when I am so hungry . Another thing is the kind of life I live , since I am IDP , it has brought me to trauma or psychological problems . Hygiene has become difficult because of the many thoughts crossing my mind like : How my children are going to eat ? How am I going to get money ? It’s difficult . ” (Female IDI participant from a comparison household)

Hunger emerged as a particularly prominent barrier to hand hygiene in this setting. At critical moments for handwashing, such as preparing or eating food, people’s hunger would override all else, causing people to forget handwashing. Hunger also caused prevented people from making plans that could facilitate handwashing. For example, participants explained that their limited daily earnings are entirely consumed by purchasing food:

“If I do not go to work in the farms all day , we shall not eat… But if you are only able to earn 2500 Congolese Francs , then all of this money will have to go on food . We ask ourselves whether to buy soap… but it is difficult to choose this rather than prioritizing food for our children . ” (Female FGD participant)

Demographic characteristics Certain personal characteristics influenced handwashing behaviour. Older adults and men who lived alone often were unable to collect sufficient water to meet their needs and therefore reported making handwashing compromises. Their reduced water availability was due to accessibility or cultural barriers associated with gender norms (i.e. generally it was only women who collected water). IDPs typically faced more challenging living conditions than host community members and often described feeling that they were living “like animal”‘ or “living a life that was not our own”. Consequently, many IDP participants reported that the ‘problem of handwashing’ was new for them and if their old lives could be restored their behaviour would also improve:

“I can tell you that I had a good life , I was a rich person … but my life changed with displacement…the situation changed to bad and today I am as you see me . take me back to my previous life and you will see my feelings and emotions will change and then I will have a high chance of washing his hands with soap . ” (Male FGD participant)

Variations in experiences of cholera and behavioural determinants between participants from case and comparison households.

The determinants of handwashing behaviour among case households were consistent with those in comparison households across the determinant categories described above. However, there were substantial differences between the two groups on cholera-related risk perceptions and the perceived or actual consequences of cholera on people’s livelihoods and routines.

Participants from comparison households . Cholera was the main health concern of almost all participants, but among those who had not had a cholera case in their household, it was seen as a common, chronic challenge that was inseparable from other adversities they faced:

“Cholera is a major health problem here … because we work hard , earn less , eat less and rest less . As consequence , we lose weight and look pale and have poor nutrition… Then it is easy for the cholera disease to attack people . ” (Female FGD participant) “It has been a long time since we do not have drinking water in this area and that is the reason why cholera disease attacked people… if you have bad food , unhealthy water and your hands are dirty then of course you will suffer from cholera . ” (Male FGD participant)

The high number of cases in the 2017 outbreak did heighten perceptions of risk and participants from comparison households reported realising cholera was serious within recent months. Participants from comparison households thought cholera generally affected children or people who were already ‘sickly’, ‘unclean’ or ‘pale’. Host community members thought that cholera was primarily a problem that affected IDPs. In terms of the social and economic impacts of cholera, participants from comparison households said they feared people who had cholera and would avoid them while infectious. Those without direct personal experiences of cholera thought its impacts on the lives of cases or their families would be relatively temporary, given that disease was seen to be easy to treat and participants felt that people tended to recover quickly. Participants were divided about whether getting cholera would have a longer-term impact on a person’s reputation:

“Someone who has had it [cholera] would not like people to know that he had it because cholera disease really affects a person’s dignity , nobody can wish to get it . It leaves you with no reputation at all . ” (Male FGD participant) “Everyone understands…I mean most people know someone who has experienced cholera at some point… So the person who gets infected , he can still recover and get back to his normalcy . ” (Male FGD participant)

In many ways local explanatory disease models were aligned with ‘Western’ biomedical messaging about the cholera (presumably because of the history of health promotion in the region). However, misperceptions about cholera persisted within the community despite familiarity with the disease. Several participants said others in their community do not take cholera seriously because they believe “black people don’t die of germs”. Similarly, some people believed that a certain degree of exposure to “dirtiness” helps to protect you because being too clean may leave you vulnerable to infection. Others felt the continued presence of cholera in Eastern DRC played to the interests of humanitarian organisations:

“We know that when [organisations] come just sensitizing about hygiene and cholera , they are paid on this—it’s no use coming all the time disturbing us . They come for their own interest . ” (Male IDI participant from a comparison household)

Over decades people had realised that most humanitarian aid was provided during cholera outbreaks. These were short term projects which subsided as cholera cases decreased. People had also learned how to make the most of a system that didn’t always appear to have their ongoing interests at heart. For example, on several occasions during our research people from the community who were not participants, approached us with lists of ‘cholera cases’ who needed help.

Participants from case households. Participants from case households reported that they were easily able to recognise cholera symptoms. All of these households explained that cholera had affected them suddenly and unexpectedly. Some participants said this in a literal sense, reflecting that people commonly went from feeling healthy to suddenly experiencing vomiting and diarrhoea which lead them to become so weak that they were unable to do anything within hours. More commonly, when participants said cholera was “unexpected” they were expressing that they struggled comprehend how the disease had been able to launch a “surprise attack” on a family like them. Participants therefore attributed their illness to a one-off “mistake” in their behaviour.

When the disease initially “attacks”, family members reported being worried. Patients described feeling “empty”, “not of this world” and “seeing only death before them”. When patients returned home from the CTC, their cholera experience was not over. Cholera cases described feeling “stuck” and “destabilized” in multiple aspects of their life. Patients were unable to do agricultural work or household tasks for about a month because they felt “weak like paper”. Given the majority of households in this region survived day-to-day, earning less than 3000 Congolese Francs per day (1.5 USD), this inability to work rapidly put families in a state of economic crisis:

“I cannot say that my economy decreased—it was totally blocked ! ” (Female IDI participant who had cholera) “A huge economic impact was observed…during that period of our child’s sickness , things really got harder . Although we generally eat badly , that particular time my husband was staying with the child at the hospital , we then ate more badly than usual because of the little amount of money—everything went really bad . ” (Female IDI participant who had a child with cholera)

People also reported that cholera affected their roles, responsibilities, and sense of self. Participants felt cholera caused their attractiveness to “fade” and that they now “hated their outlook” due to the amount of weight they had lost. Parents who had been cholera cases felt worried that in the months following their discharge they had become unable to care and provide for their children:

“I became like a baby…I had to wait for somebody else to take care of me , like the neighbours , it is like I have lost my role of mother to all these children . ” (Female IDI participant who had cholera) “Suffering from cholera reduced considerably my responsibility as a father , I could not feel respected , and I could not feel myself as a father of the family because I was half-dead . ” (Male IDI participant who had cholera)

Another woman explained that she relied on her neighbour to breastfeed her new born baby for several months while she was sick with cholera. Children and older members of the household often had to stand in for parents to do the household chores. Relationships with neighbours and friends also changed. Some participants explained neighbours were integral in helping them through their recovery and that they often gave them food, money and water (although it was expected the household would find a way to pay this back):

“I am still feeling weak and have no money to buy food because I am not working , so some neighbours give me food to eat , but you understand how difficult it is to depend on someone else’s kitchen . ” (Female IDI participant who had cholera)

Others explained that neighbours and friends stayed away following their illness and that they felt isolated and stigmatised:

“The relationship with neighbours does change because of gossip , they start saying that it is because of your uncleanness…they end up avoiding you” (Man IDI participant who’s elderly brother had cholera) “I lived an isolated life during those hard periods of cholera cases . ” (Female IDI participant who had 3 children who had cholera)

However, participants from case households reported being more motivated to wash their hands, explaining this was because they recognised their vulnerability to disease. They also used handwashing as a way of countering any misperceptions from neighbours about their cleanliness. The latter concern seemed to prompt a range of demonstrative action around handwashing. For example, several participants said they have actively encouraged others to practice handwashing:

“Though we got infected, we cannot feel discouraged from doing hygiene practices…we even try to improve it and we are telling our neighbours that they should keep on practicing hygienic behaviour because that is the only way to prevent cholera…And other people around here, when they see how clean you are, even if you got sick with cholera, they can decide to take you as their good example of cleanliness” (Male IDI participant who had 2 children with cholera)

One participant built a dedicated place for handwashing near the toilet after his daughter was admitted to hospital with cholera:

“I realise that fighting this cholera disease is very serious these days and so I thought that once we are practicing hand washing , we will be able to prevent our family from this disease…So I decided I had to make the place for handwashing , a place that would be respected … Now the neighbours are just appreciating [the facility] and I am telling them to do the same as I did , but whether they agree or not , I will never give up with the practice . ” (Male IDI participant whose daughter had cholera)

However, households with cholera cases also felt their circumstances following their exposure to the disease made it more challenging to practice handwashing. This was due to their reduced physical health, their inability to collect sufficient water (most households reported being able to access half as much water in the period post discharge as compared to their normal circumstances), increased hunger and malnutrition (due to loss of income), and difficulties affording other basic daily necessities, such as soap. A minority of participants were given a small bar of soap and six water purification tables upon discharge from the CTC. Participants who received these distributions, reported trying to use these sparingly to make them last as long as possible.

Our research found that in the Eastern region of DRC, cholera is generally conceptualised as a persistent and commonplace health challenge but also one that is easily treatable. Frequent hygiene promotion sessions in this region have led to high levels of knowledge about the health impacts of cholera, its symptoms and recommended preventative behaviours. However, handwashing with soap was observed to be rare in this setting. By using theory-driven qualitative methods we were able to identify that this was because the psychological, social, and environmental behavioural determinants affecting handwashing in this context combined to limit the ability of individuals to improve their handwashing behaviour. Major barriers to handwashing related to the physical environment or behavioural setting included the absence of handwashing facilities, water scarcity, the unaffordability of soap, the small make-shift houses where displaced populations lived, the use of shared sanitation facilities, and the extended periods people spent working outside of the home. Handwashing behaviour was also hampered by broader experiences of living in poverty and within in a dynamic conflict-prone region with high rates of displacement and livelihood fragility. This was because handwashing was often deprioritised because of hunger, mental health challenges, the unpredictability of routines, and the lack of social support and sanctions around handwashing. The experiences of participants from case households indicated that in complex crises, cholera can have profound non-health impacts on a household’s income, productivity, social status, and sense of control–factors which in turn create additional barriers to handwashing.

Despite low rates of actual handwashing practice, our research participants reported handwashing had increased as concerns about cholera were heightened. Many participants felt these changes in behaviour might be sustained beyond the outbreak. Prior literature has indicated self-reported handwashing behaviour tends to increase during outbreaks [ 15 , 27 – 31 ], however, studies which use observational measures of behaviour show much lower rates of practice even during outbreaks [ 32 ]. Such findings act as a reminder that research exploring handwashing behaviour should prioritise including observational methods to gauge actual practice given that self-reported behaviour is commonly affected by social desirability bias, and that this bias may be heightened in outbreaks [ 33 ]. However, it may also be indicative how behaviour may fluctuate over the course of outbreaks. For example, initial gains in the frequency of handwashing behaviour at the onset of an outbreak seem to decline or vary over time as fear associated with the disease subsides or the disease is normalised [ 27 , 34 , 35 ]. One handwashing study published during the COVID-19 pandemic suggested that such patterns in behaviour may be explained through Terror Management Theory (TMT) [ 35 ]. This theory suggests that when the threat to our mortality from a disease is made more salient, we are more likely to adopt health behaviours, like handwashing, that can remove this threat from our focal attention [ 35 – 37 ]. This theory also explains that when the disease threat is no longer the focus of our attention, protective behaviours may start to decline. In our study participants were aware of the proximal threat of cholera in their region but adopted other psychological defences (such as perceiving others to be at greater risk than them and believing “black people don’t die of germs”) which avoided the threat and made this reality easier to cope with on a day-to-day basis. TMT might also explain why case households were more driven to take demonstrative action around handwashing following their recent brush with death. In contrast, comparison households in our study site were pre-occupied by more salient threats to their mortality such as hunger and conflict. As such their daily behaviour was geared to the reduction of these threats rather than cholera prevention behaviours. There are few studies which explore how stress or external threats may affect the prioritisation of handwashing behaviour, however, consistent with our results, one study among health care workers in a high-income setting indicated that stress, cognitive load and threats to mortality that appear more urgent or proximal, may impair a person’s ability to practice handwashing [ 38 ]. Our findings challenge the common belief that if people understand the benefits of handwashing they will act ‘rationally’ during an outbreak and wash their hands more frequently to protect themselves and others [ 16 , 39 ].

In our study, households with cholera cases experienced the disease as an exogenous shock to their already vulnerable state which plunged their household into a state of acute socio-economic crisis. This household-level crisis was characterised by a sudden but extended loss of income, increased hunger, isolation from social support systems, feeling unable to provide for family members, and feeling that their exposure to cholera may tarnish their social standing in the long term. These lived experiences of cholera are consistent with existing, but limited, literature from other settings where cholera outbreaks occur during complex crises or within fragile states and among populations with high levels of poverty [ 40 , 41 ]. Our study found that exposure to cholera decreased the household’s access to food and made it hard to prioritise handwashing due to a reduced ability to access water purchase soap in the wake of their illness. This presents a critical challenge for cholera control given that hand hygiene is likely to be key to interrupting transmission during the 10 days when cases are hyper-infective following infection [ 42 ] and v . cholerae continues to be shed in their faeces. There is also some evidence that pre-existing and continued malnutrition during this period may prolong shedding [ 6 ]. Our findings support the likely effectiveness of targeted WASH interventions distributions of hygiene kits [ 12 , 43 ] and suggests that these could be complemented by the distribution of food items in some settings.

Prior research in this region of DRC has highlighted that hygiene programming may be met with reduced acceptability if it is inadequately resourced, poorly contextualised, fails to acknowledge other priorities of the population, or does not address social and environmental factors that may constrain behaviour [ 44 , 45 ]. Broader research has also indicated that during complex crises, experiences and responses to cholera outbreaks are associated with, and amplified by, structural and social vulnerabilities such as extreme poverty, conflict and displacement [ 46 – 48 ]. Our findings are consistent with this body of research and indicate that hygiene programming aimed at mitigating cholera transmission amid complex crises is likely to be more effective if it is integrated into longer-term initiatives that focus on these larger vulnerabilities, such as food security, livelihoods and psychosocial support initiatives. In contexts where cholera is endemic, handwashing programmers must move beyond health-education and work with communities to build enabling environments through investment in handwashing facilities and reliable water supply systems, and supportive social structures. Participants in our study highlighted the importance of conveniently located, desirable and durable facilities in cueing behaviour at key times and this is supported by broader literature [ 15 ]. Our research also identified examples of adaptive coping strategies utilised by the population to facilitate handwashing behaviour, reduce vulnerability, and increase their sense of control over the unpredictability of their circumstances. Coping strategies included the use of surface water or grey water for handwashing, the use of ash when soap was unavailable, the pooling or water and soap resources within compounds, the careful calculation of water and soap use to facilitate all necessary household tasks and encouraging neighbours to remind all children within a compound about handwashing. While these actions were taken by a minority of households in our study, they could easily be shared and adopted by others by utilising a positive deviance approach [ 49 ]. Research in previous outbreaks has highlighted the importance of understanding whether local coping mechanisms are aligned with, juxtaposed to, or are able to fill gaps in government and organisation-led disease prevention strategies [ 50 – 52 ]. Experiences during prior outbreaks has also emphasised that an overreliance on biomedical explanations of disease can be met with resistance from populations [ 16 , 53 , 54 ]. If health promotion fails to acknowledge emic perspectives and experiences it has the tendency to isolate the disease from its human host and the social experiences that facilitate transmission [ 55 ]. Our findings suggest that handwashing programmes should aim to change the public health discourse around cholera-related risk by focusing on local constructions of disease, the experiences of populations, and by communicating the non-health impacts of the disease. This may allow populations to adjust their decision-making and coping mechanisms towards prioritising behaviours like handwashing—particularly if it is seen to have health, social and economic benefits in the long term. Lastly, our research found that case households were more motivated to practice handwashing after their exposure and were better able to act upon their behavioural intentions to encourage the behaviour in others and create an enabling physical environment for handwashing. Humanitarians could build upon this by inviting cholera cases to share their experiences with others in the community. There is some evidence that this may be an effective way to motivate health behaviour, challenge misperceptions around diseases and to heighten perceived vulnerability in a way that is more sustainable than focusing on fear alone [ 56 ].

Limitations

Our research was primarily interested in exploring how the determinants of handwashing behaviour were affected by a cholera outbreak. While observed and self-reported behaviours are described qualitatively in this study, the methods were not designed to be representative and therefore this data could usefully be complemented by further research which measures actual behaviour before, during and after outbreaks in regions that are prone to them.

Where possible we used participatory activities that have been used in prior research however some new approaches were developed to explore motives, water prioritisation and experiences of conflict. Replication of these methods would be useful to demonstrate their validity and reliability.

Our sampling was guided by case lists from the CTC, however in this region cholera case admission is not always laboratory confirmed. Other research from DRC has shown that only a minority of those admitted to CTCs actually had cholera [ 57 ] and therefore this may skew some of our research findings in relation to experiences of the disease. As noted, cholera was often used by research participants to be a catch all term for diarrhoeal diseases, this emic construction may have therefore also distorted the way people described their experiences and perceptions in relation to the disease.

This research was conducted in partnership with Action Contre la Faim and for security reasons our research team were required to wear a branded vest throughout data collection and travelled in a branded vehicle. Given that the organisation have a history of working on WASH projects in this region and that participants had been exposed to decades of humanitarian response programmes, this may have increased willingness to participate and resulted in more socially desirable answers. The research team tried to reflect on this during daily research discussions and consider how our individual and collective positionalities may have shaped our findings.

In addition to having severe health implications, outbreaks have the potential to disrupt people’s social, psychological, and economic lives. By focusing on the lived experiences of cholera, our research highlighted that even when substantial shifts in behavioural determinants occur, it is not always enough to substantially influence the uptake of preventive behaviours like handwashing with soap. In this case, handwashing behaviour remained low during the outbreak due to the absence of enabling physical and social environments and the competing priorities and vulnerabilities of the population. Handwashing programmes targeting areas with endemic cholera or outbreaks within complex crises could be strengthened by acknowledging the underlying circumstances that create and perpetuate outbreaks, addressing the health and non-health impacts of diseases like cholera, investing in sustainable handwashing infrastructure, and identifying and sharing local disease coping mechanisms that facilitate the practice of preventative behaviours.

Supporting information

S1 table. handwashing determinant definitions adapted from on the bcd checklist of determinants (1, 2) and accompanied by method selections..

https://doi.org/10.1371/journal.pone.0266849.s001

S2 Table. Description and sample size for all methods done at a household or individual level.

https://doi.org/10.1371/journal.pone.0266849.s002

S3 Table. Purpose, description and sample size for each of the methods done within group discussions.

https://doi.org/10.1371/journal.pone.0266849.s003

S4 Table. Inclusivity questionnaire.

https://doi.org/10.1371/journal.pone.0266849.s004

S5 Table. Identified determinants and their associated influence on handwashing behaviour in Eastern DRC.

https://doi.org/10.1371/journal.pone.0266849.s005

Acknowledgments

We would like to thank the following people for helping to facilitate the research and contributing to ongoing reflections about emergent insights: Isiaka Hemedi, Justine Badhera Habamungu, Léon Ngwasi, Batian Arthur Benao, Marie-Paul Chirimwami, Karine Le Roch, Jean Lapegue and representatives of the Goma WASH Cluster. We would particularly like to thank the individuals who gave of their time to participate in this research and who welcomed us into their homes and shared their personal experiences so openly.

This research was undertaken as part of the Wash’Em Project which aims to improve handwashing promotion in humanitarian crises. The contents are the responsibility of the authors of the paper and do not necessarily reflect the views of our donors, USAID or the United States Government.

• 1. Global Task Force on Cholera Control. Ending Cholera: A Global Roadmap to 2030. 2017.
• View Article
• PubMed/NCBI
• Google Scholar
• 25. Schatzman L, Strauss AL. Field research: Strategies for a natural sociology: Prentice Hall; 1973.
• 27. Babalola S, Krenn S, Rimal R, Serlemitsos E, Shaivitz M, Shattuck D, et al. KAP COVID Dashboard. In: Johns Hopkins Center for Communication Programs GOAaRN, Facebook Data for Good., editor. Massachusetts Institute of Technology, 2020.
• 36. Pyszczynski T, Solomon S, Greenberg J. Chapter One—Thirty Years of Terror Management Theory: From Genesis to Revelation. In: Olson JM, Zanna MP, editors. Advances in Experimental Social Psychology. 52: Academic Press; 2015. p. 1–70.
• 40. ‘People Were Dying Like Flies’: The Social Contours of Cholera in Harare’s High-Density Townships. In: Chigudu S, editor. The Political Life of an Epidemic: Cholera, Crisis and Citizenship in Zimbabwe. Cambridge: Cambridge University Press; 2020. p. 155–83. https://doi.org/10.1016/S2214-109X(20)30249-7 pmid:32416766
• 42. World Health Organisaiton. Cholera Fact Sheet WHO Website: WHO; 2021 [Available from: https://www.who.int/news-room/fact-sheets/detail/cholera ].
• 55. Abdalla M, editor Beyond Biomedicine: Sub-Saharan Africa and the struggle for HIV/AIDS discourse2014.

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• v.143(4); 2015 Mar

Cholera in the United States, 2001–2011: a reflection of patterns of global epidemiology and travel

A. loharikar.

1 Office of Workforce and Career Development, Centers for Disease Control and Prevention, Atlanta, GA, USA

A. E. NEWTON

2 Enteric Diseases Epidemiology Branch, Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA

3 Enteric Diseases Laboratory Branch, Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA

K. D. GREENE

M. b. parsons, d. talkington, e. d. mintz.

4 Waterborne Disease Prevention Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA

B. E. MAHON

US cholera surveillance offers insight into global and domestic trends. Between 2001 and 2011, 111 cases were reported to the Centers for Disease Control and Prevention. Cholera was associated with international travel in 90 (81%) patients and was domestically acquired in 20 (18%) patients; for one patient, information was not available. From January 2001 to October 2010, the 42 (47%) travel-associated cases were associated with travel to Asia. In October 2010, a cholera epidemic started in Haiti, soon spreading to the Dominican Republic (Hispaniola). From then to December 2011, 40 (83%) of the 48 travel-associated cases were associated with travel to Hispaniola. Of 20 patients who acquired cholera domestically, 17 (85%) reported seafood consumption; 10 (59%) ate seafood from the US Gulf Coast. In summary, an increase in travel-associated US cholera cases was associated with epidemic cholera in Hispaniola in 2010–2011. Travel to Asia and consumption of Gulf Coast seafood remained important sources of US cholera cases.

INTRODUCTION

Cholera continues to ravage populations in many developing countries, most recently in Haiti and the Dominican Republic, the two countries that form the island of Hispaniola [ 1 , 2 ], although cholera transmission and effective measures for its prevention have been understood for over 150 years [ 3 , 4 ]. For over a century, most cases of cholera identified in the United States have been associated with travel to countries with endemic cholera [ 5 – 9 ]. Domestically acquired cases are primarily associated with the consumption of raw or undercooked seafood harvested from the US Gulf Coast [ 10 – 12 ]. Periodic reviews of US cholera surveillance offer a window on the global cholera situation; this report summarizes cholera cases diagnosed in the United States during 2001–2011.

Cases of cholera that occur in the United States are reported by state and local health departments to the Centers for Disease Control and Prevention (CDC) via the Cholera and Other Vibrio Illness Surveillance (COVIS) system [ 13 ]. CDC requests isolates from all suspected cases for confirmatory testing. A confirmed case of cholera is defined as an illness characterized by diarrhea, vomiting, or both with (1) isolation of toxigenic Vibrio cholerae serogroup O1 or O139 from stool or vomitus or (2) serological evidence of recent O1 infection, defined as a vibriocidal antibody titre ⩾640 in acute or early convalescent phase sera in a person epidemiologically linked to a confirmed cholera case. Data reported to COVIS include demographic, clinical, and exposure information, including domestic and international travel and seafood consumption within 7 days of illness onset. A travel-associated case is defined as cholera in a person who travelled outside the United States during the 7 days before illness onset; cases in persons who report no such travel are considered domestically acquired, and cases in persons for whom information about travel is not available are categorized as unknown. If more than one destination country is reported, exposure is assumed to have occurred where cholera is currently circulating. Cases reported to COVIS with onset from 1 January 2001 to 31 December 2011 were included in this review.

All V. cholerae serogroup O1 and O139 isolates are confirmed on the basis of agglutination in specific antiserum. Boiled lysates of V. cholerae are amplified by polymerase chain reaction (PCR) to detect the presence of cholera toxin ( ctxA ) [ 14 ], biotype-specific ( tcpA ) genes [ 15 ], and species-specific gene sequences ( ompW, toxR ) [ 16 , 17 ]. Molecular subtyping by pulsed-field gel electrophoresis (PFGE) is conducted [ 18 ]. The resulting PFGE patterns are analysed using BioNumerics software (Applied Maths, USA) and uploaded to the Vibrio cholerae National PulseNet database where comparisons to previously reported V. cholerae isolates are conducted. PulseNet is the national molecular subtyping network for foodborne bacterial pathogens. Susceptibility testing of toxigenic V. cholerae isolates is performed by the disk diffusion method for the following antimicrobials: kanamycin (included in testing until 2010), amoxicillin-clavulanate (included in testing beginning in 2010 for patients who reported travel to Haiti), ampicillin, chloramphenicol, ciprofloxacin, furazolidone, nalidixic acid, streptomycin, sulfisoxazole, trimethoprim-sulfamethoxazole and tetracycline, in accordance with Clinical Laboratory Standards Institute (CLSI) recommendations [ 19 , 20 ]. Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853 were used as internal quality controls. Interpretive criteria specific for V. cholerae were applied when available [ 19 ], or CLSI criteria for Enterobacteriaceae were used [ 20 ].

Demographic and clinical information

COVIS received reports of 111 confirmed cases of cholera diagnosed in the United States between 1 January 2001 and 31 December 2011. Cases were reported by 27 states and two territories ( Fig. 1 ) with onset dates ranging from 7 April 2001 to 21 November 2011 ( Fig. 2 ). A marked increase in reports occurred after epidemic cholera began in Haiti in October 2010; 46% of all cases over the 11-year study period were reported in the subsequent 14 months.

States and US territories reporting cholera cases, 2001–2011 ( n  = 111 cases).

Number of cholera cases by year, and by source 2001–2011, United States ( n  = 111 cases).

Fifty-six patients (50%) were female. Patients’ median age was 44 years (range 1–85 years); nine (8%) were aged <10 years, 95 (86%) were 10–64 years and 17 (15%) were ⩾65 years ( Table 1 ). Of the 111 patients, 109 (98%) reported diarrhoea, and 52 (47%) reported vomiting. Other reported symptoms included abdominal cramps (52%), nausea (46%), fever (14%), muscle aches (13%), headache (11%), and blood in stool (5%). Of the 90 patients with available information, 56 (62%) were hospitalized. In hospitalized patients with severe complications, four (4%) patients had acute renal failure, two (2%) had cardiopulmonary arrest, and one (1%) had shock; none died. In all, 81 (73%) patients received an antimicrobial agent for treatment.

Cholera cases by age group and source, 2001–2011, United States (n = 111 cases)

Exposures (source of illness)

Travel-associated cases.

In 90 (81%) patients, cholera was travel-associated. Travel to Hispaniola accounted for 40 (44%) cases (Haiti, 29; Dominican Republic, 11), to South Asia for 35 (39%) cases (India, 17; Pakistan, 13; Bangladesh, 4; Nepal, 1), to Southeast Asia for 13 (14%) cases (Philippines, 8; Indonesia, 3; Thailand, 2); and to West Africa for two (2%) cases (Ghana, 1; Benin, 1). The 42 travel-associated cases with onset from January 2001 to 21 October 2010 were all associated with travel to South and Southeast Asia. After 21 October 2010, 40 (83%) of the 48 travel-associated cases were associated with travel to Hispaniola.

Travel-associated cases were reported by 27 states. Most of the 40 cases associated with travel to Hispaniola were reported by Florida (14 cases) and New York (12 cases); 10 other states reported the other 14 cases associated with travel to Hispaniola. The 49 cases associated with travel to destinations other than Hispaniola were more widely distributed across the United States, with 22 states reporting cases with no more than eight reports from a single state.

Reported reasons for travel included visiting friends and relatives (62%, including nine who attended a wedding in the Dominican Republic on 22 January 2011 [ 21 ]), tourism (7%), business (7%), medical missions or other relief work (9%, most with travel to Hispaniola), and immigration to the United States (5%); information on the reason for travel was not available for 12%.

Domestically acquired cases

Twenty (18%) domestically acquired cases were reported by seven states and one territory; 19 (95%) reported seafood consumption. Ten (50%) were associated with consumption of Gulf Coast seafood; seven of these patients resided in Louisiana. Gulf Coast seafood consumed included: raw oysters (two cases), boiled and/or raw crabs (eight cases), cooked shrimp (five cases), and fish (three cases). The other 10 (50%) domestically acquired cases included six patients with a history of non-Gulf Coast seafood consumption for whom the source of seafood was not known, three patients with a history of imported seafood consumption (reheated conch imported from Haiti for one, fried shrimp imported from either Nicaragua or Indonesia for one, and raw shrimp imported from Asia for one) and one patient who reported eating no seafood (a young child whose source was unclear but who had contact with travellers from Pakistan). Of the 19 patients with domestically acquired cholera who reported seafood consumption, eight (47%) consumed the seafood raw.

Unknown source

One (1%) patient was lost to follow-up, so no information about either the location or the likely source of exposure was available.

Laboratory results

Cholera was confirmed by isolation of toxigenic V. cholerae from stool in 108/111 cases; 107 (96%) stool specimens yielded V. cholerae serogroup O1, all biotype El Tor; 22 (21%) were serotype Inaba, and 85 (79%) were serotype Ogawa ( Table 2 ). One (1%) stool specimen collected in 2009 yielded serogroup O139; the patient had domestically acquired cholera and reported consuming imported raw shrimp purchased from a seafood market specializing in Asian foods. Three cases (3%, all in patients with a history of travel to Hispaniola) were confirmed serologically.

Laboratory characterization on isolates of V. cholerae O1, including serogroup/biotype, PFGE pattern, and antimicrobial resistance pattern, United States, 2001–2011 (n = 107)

PFGE, Pulsed-field gel electrophoresis.

PFGE results were available for 93 (87%) V. cholerae isolates ( Table 2 ). The PFGE pattern combinations of 45 (48%) serogroup O1 isolates were indistinguishable from isolates obtained from patients in Hispaniola, [ 21 , 22 ] labelled the ‘Haiti pattern’. Of these 45 patients, 26 (60%) reported travel to Haiti, 10 (22%) to the Dominican Republic, five (11%) to India, one to Pakistan (2%), one (2%) to Benin; two (4%) reported no travel but consumed imported seafood (from Haiti for one and from either Indonesia or Nicaragua for the other). The PFGE pattern combinations of nine (10%) serogroup O1 isolates from patients with domestically acquired cholera associated with exposure to seafood from the Gulf Coast, labeled the ‘Gulf Coast strain,’ were indistinguishable from each other and from the established pattern of the Gulf Coast strain [ 23 ]. Of the remaining 39 serogroup O1 isolates, labelled ‘Other patterns’, 23 reported travel to South Asia [nine (39%) each to India and Pakistan, four (17%) to Bangladesh, and one (4%) to Nepal]; eight to Southeast Asia [five (63%) to the Philippines) and three (38%) to Indonesia]; five reported no travel; and one had unknown exposure, but was a resident of Guam. The PFGE pattern of the serogroup O139 isolate was similar but not identical to PFGE patterns of serogroup O1 and O139 isolates from patients who had travelled to countries in Southeast Asia.

Antimicrobial susceptibility testing was conducted on all 107 V. cholerae O1 isolates and defined three major antibiotic susceptibility pattern complexes ( Table 2 ). The first is a pan-susceptibility pattern, in which isolates were susceptible to all antimicrobial agents tested. This pattern was seen only in the 10 isolates from patients whose source of infection was Gulf Coast seafood. The second is a complex of multi-drug resistance (MDR) patterns, in which isolates were susceptible to agents from at least five CLSI classes. These MDR patterns were seen in isolates from travellers to Hispaniola ( n  = 37), South Asia ( n  = 35), Africa ( n  = 2), and in several domestically acquired cases that were not linked to Gulf Coast Seafood ( n  = 3). All were resistant to nalidixic acid, and all but four (two from travellers to Bangladesh in 2007 and 2011, one traveller to India in 2008, and one traveller to Pakistan in 2010) were susceptible to tetracycline. The third pattern complex included isolates resistant to furazolidone alone (one was also resistant to nalidixic acid); it was seen in the 13 isolates from travellers to Southeast Asia as well as in seven domestically acquired cases that were not linked to Gulf Coast seafood. Antimicrobial susceptibility testing was also conducted on the isolate of V. cholerae O139; it was resistant to nalidixic acid, streptomycin, sulfisoxazole and trimethoprim-sulfamethoxazole, but was susceptible to furazolidone and the other agents in the panel.

Our review of cholera in the United States from 2001 to 2011 confirms the truth of the saying that even rare and apparently exotic infectious diseases are just an airplane ride away. Less than a month after cholera was first noted in Haiti in October 2010, cases associated with that outbreak had been diagnosed in the United States [ 24 , 25 ]. In 2011, more than twice as many US cases of cholera were associated with travel to Haiti than had been reported from all sources in any year over the previous decade, reminiscent of the pattern seen in the early 1990s with the outbreaks of cholera in Latin America [ 8 ]. Cholera has now become endemic in Haiti and has been imported from Hispaniola to Canada, Spain, Venezuela, and possibly Cuba [ 21 , 26 ]. Endemic transmission of cholera persists in the Dominican Republic and Cuba, as in Haiti, and poses a continued threat of travel-associated cases, particularly to the United States and the rest of the Western hemisphere.

Travel to Asia and consumption of raw or undercooked seafood continue to be sources of cholera in the United States [ 7 – 9 ]. Cases associated with travel to other cholera-affected countries, primarily in Asia, were reported throughout the review period, with no sign of decrease. The incubation period of cholera is short – typically 12 h to 2 days – so it is likely that additional cases occur while travellers are abroad and are not captured by this surveillance system. Long travel times from Africa and Asia may mean that cases in travellers to these areas are especially likely not to be diagnosed in the United States. Although sanitation standards in the United States make sustained transmission unlikely, cholera and other waterborne diseases are likely to continue to be imported until safe water and adequate sanitation are available to all worldwide. Several cases were associated with consumption in the United States of raw or undercooked seafood, including not only seafood harvested from the Gulf Coast, a focus of V. cholerae O1 first described in the late 1970s [ 10 ], but also imported seafood.

Different states have had markedly different experiences with cholera. Most cases associated with travel to Hispaniola were reported from just two states, New York and Florida. As these are the states with the largest populations of Haitians and Dominicans – Florida (251 963, 46%), New York (135 836, 25%) – this pattern is not surprising, but it is a reminder of the need for culturally and linguistically appropriate medical care and public health response [ 27 ]. In Florida, for example, the state health department produced educational materials on cholera in Haitian Creole for patients and their contacts that greatly facilitated response. Cholera cases associated with travel to other countries, by contrast, were reported by 22 states, with no more than eight cases from any state. Most of these patients had travelled to South Asia or Southeast Asia; only two cases were associated with travel to Africa, although many African countries have been hit hard by cholera in recent years [ 28 , 29 ]. The relative lack of US cases associated with travel to Africa likely reflects, at least in part, low numbers of travellers, relative to other destinations. A pattern of relatively low numbers of cases – but high risk per traveller – has been reported for other enteric infections [ 30 ]. Domestically acquired cholera predominantly affected the Gulf Coast states of Louisiana and Texas, as in years past. In sum, healthcare providers and public health authorities in all states should be prepared to diagnose, treat, and respond to cases of cholera.

Strategies for prevention of cholera in US residents depend to a great extent on the exposure scenario. Of patients with travel-associated cholera, 62% travelled to visit friends or relatives (VFR) in another country. These types of travellers are less likely than others to seek medical consultation before travel and may also perceive less risk from food and water while travelling [ 30 , 31 ]; they can be hard to reach with prevention messages. Other travellers reported travelling for tourism, business, or medical missions or other relief work. Notably, since their risk of exposure may be particularly high, these types of travellers are relatively likely to receive pre-travel medical consultation, which can stress the importance of safe water and food in preventing not only cholera, but many other enteric infections as well. There are currently two WHO-prequalified vaccines available outside the United States. Although no cholera vaccines are currently available in the United States, a cholera vaccine intended for US travellers is in development [ 32 ]; its use would require a pre-travel healthcare visit. Although we have no data on the proportion of patients who sought pre-travel care, among those for whom information on reason for travel was available and who were not residents of another country, only 24% were not travelling to visit friends or relatives. For a vaccine to have optimal impact, strategies to reach VFR travelers would be needed. Regarding the potential impact of a vaccine for travellers, it is important to note that US surveillance captures only cases diagnosed in the United States. Finally, prevention of domestically acquired cholera lies squarely in the realm of food safety; the great majority of cases are associated with consumption of raw or undercooked seafood.

Cholera has a well-deserved reputation as a severe, often fatal disease, but prompt and appropriate therapy can all but eliminate fatalities. In our review, 98% of patients reported diarrhoea; 62% of those with information on hospitalization were hospitalized. Although none died, several developed severe complications including acute renal failure, cardiopulmonary arrest, and shock. These severe complications from profound dehydration speak to the need for clinicians to be aware of cholera and prepared to treat it appropriately [ 33 , 34 ]. Importantly, because dehydration progresses rapidly after onset of diarrhoea, patients must be able to access care within a few hours of symptom onset. If a traveller is en route or far from healthcare, cholera gravis can lead to death before a patient reaches a treatment facility. CDC has advised that pre-packaged oral rehydration salts be carried on international flights to address this need [ 35 ]. Treatment with antimicrobial agents is adjunctive but can shorten the duration of symptoms and V. cholerae shedding [ 36 ]. Several public health organizations recommend doxycycline (an antimicrobial in the tetracycline class) as first-line therapy and ciprofloxacin (an antimicrobial in the quinolone class; resistance to nalidixic acid correlates with decreased susceptibility to ciprofloxacin) as an alternative. In our review, isolates from patients whose source of cholera was travel to Southeast Asia or Gulf Coast seafood were susceptible to these agents (except for one isolate from a patient with domestically acquired cholera who ate seafood of unknown source, which was resistant to nalidixic acid). Isolates from patients who had travelled to Hispaniola, South Asia, and Africa, as well as some who acquired cholera domestically from sources other than Gulf Coast seafood were uniformly resistant to nalidixic acid, but most were susceptible to tetracycline. Within sources of exposure, these resistance patterns did not vary over the period of our review. Macrolide antibiotics are also recommended by some organizations as an alternative agent, but macrolides are not included in the panel of agents tested.

Healthcare providers in the United States should consider cholera in patients, especially adults, with severe watery diarrhoea. The level of suspicion should be heightened for patients with a history of international travel to cholera-endemic regions or of consuming raw or undercooked seafood from the Gulf Coast or elsewhere. Cholera is most often diagnosed by stool culture on thiosulfate citrate bile salts sucrose (TCBS) medium, which in most settings must be specifically requested by the clinician. State and local public health laboratories should send all V. cholerae isolates to CDC for confirmatory testing and subtyping by PFGE or, as they become available, newer methods such as whole genome sequencing. CDC can also measure vibriocidal and anti-cholera toxin antibodies in serum.

As with other notifiable infections, surveillance data on cholera in the United States is limited both by under-diagnosis and by under-reporting. Patients may not seek medical care for mild cases, and healthcare providers may not make a specific diagnosis even in severe cases. Reporting by providers and clinical laboratories to states is passive and by state health departments to COVIS is both passive and voluntary. However, under-reporting per se is unlikely to be a major source of bias; a recent comparison of COVIS data to FoodNet active surveillance data showed similar patterns of incidence and trends in Vibrio infections in both systems. Nonetheless, our data should be viewed as a minimal estimate of cholera in the United States.

In summary, this review of US cholera early in the 21st century describes another important chapter in the history of cholera in the United States. This history includes, in the late 1970s, the discovery of the Gulf Coast strain of V. cholerae O1 [ 10 ]; in the early 1990s, a surge of cases associated with epidemic cholera in Latin America [ 37 – 39 ]; in the late 1990s and early 2000s, a relative lull during which most cases were associated with travel to Asia [ 7 , 8 ]. Now, in the second decade of the new millennium, we are witnessing a marked increase in cases associated with the new epidemic in Hispaniola. Throughout, prevention has depended on basic standards of safe water, sanitation, and food safety. To the extent that the United States can maintain these standards at home and foster their development abroad, it can both protect its own population and contribute to efforts to improve public health in other countries [ 4 ].

ACKNOWLEDGEMENTS

The authors acknowledge the following individuals and groups for their contributions to this work: Patricia Yu, Kelly Jackson, Robert Tauxe, Patricia Griffin, Maurice Curtis, Jessica Halpin, the PulseNet PFGE Laboratory, state and local public health departments.

The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.

Much of the material in this paper was presented at the 2012 Infectious Diseases Week Conference in San Diego, CA. A small subset of the cases, the first 23 cases diagnosed in the United States associated with the epidemic in Haiti and the Dominican Republic, was published in Emerging Infectious Diseases in 2011. This paper is referenced in our manuscript (Newton et al. [ 25 ]); it includes about 20% of the cases and <5% of the time on which we report.

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Cholera in yemen: a case study of epidemic preparedness and response.

• Johns Hopkins Univ.

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EXECUTIVE SUMMARY

BACKGROUND:

In 2015, the United Nations (UN) declared Yemen a Level 3 (L3) emergency. On September 28, 2016, a largescale cholera outbreak began. Between April 27, 2017 and July 1, 2018, more than one million suspected cases in two waves were reported. In the last decade, several large-scale and high mortality cholera outbreaks have occurred during complex humanitarian emergencies including in Iraq, Somalia, and South Sudan. While the issues of “what to do” to control cholera are largely known, context-specific practices on “how to do it” in order to surmount challenges to coordination, logistics, insecurity, access, and politics, remain. During the Yemen cholera outbreak response, questions arose concerning how to effectively respond to a cholera outbreak at a national scale during an existing L3 emergency. The Office of U.S. Foreign Disaster Assistance (OFDA), supported by the Department for International Development (DFID) and the European Civil Protection and Humanitarian Aid Operations (ECHO), provided funding to the Johns Hopkins Center for Humanitarian Health for an unsolicited proposal for a case study of the response.

OBJECTIVES AND METHODS:

The main objective was to identify lessons from September 28, 2016 to March 2018 (i.e., from the preparedness and detection phase to the end of second wave) to better prepare for future cholera outbreaks in Yemen and similar contexts. The methods included: literature reviews of global cholera guidance, cholera and other outbreak management in complex humanitarian emergencies and fragile states, and documents relating to the outbreak in Yemen; interpretation of surveillance data; and, key informant interviews (KII) with practitioners, donors, and technical experts involved in the response.

114 documents were reviewed, and 71 KIIs were undertaken.

Reports from Iraq, South Sudan, Haiti, and other complex emergencies and fragile states highlight substantial adaptations undertaken to manage cholera outbreaks. Global cholera guidance emphasizes the early detection and response to contain outbreaks at an early stage, a multi-sectoral approach to prevent cholera in hotspots in endemic countries, and effective mechanisms of coordination for technical support, resource mobilization, and partnership.

Prior to the outbreak, Yemen did not have a sufficient cholera preparedness and response plan. There was no plan despite previous cholera outbreaks, endemicity in the region, active conflict, and World Health Organization (WHO) regional office initiatives.

The 2016 cholera response plan evolved iteratively, but did not initially prioritize standard components. Initial gaps including epidemiological analysis to inform the response, and reference to the oral cholera vaccine, community surveillance, and infection prevention and control as well as emerging problems (e.g., improvement of laboratory capacity and monitoring of the application of the case definition).

The surveillance and laboratory systems were insufficiently prepared and inadequately modified to monitor the cholera epidemic during a complex emergency. The large number of suspect cases reported is likely much higher than the actual number meeting the suspect case definition. The lack of systematic use of culture-confirmation and the late adoption of epidemiological investigation and quality control made it difficult to address the high proportion of mild suspect cases. Extensive human resources and logistics were applied to sustain the response, proportionate to caseload, at a national level. Multiple contributing factors included: culture confirmation needs surpassing the capacity of the only two authorized laboratories; an incentive payment structure inadvertently promoted the inclusion of patients who did not meet the suspect case definition; and lack of early implementation of a system to remotely monitor reporting practices in insecure areas.

The treatment network of case management units (diarrhea treatment centers (DTCs) and oral rehydration corners (ORCs)) were insufficiently decentralized and did not ensure adequate access for as much of the population as could have been achieved. The strategy focused on establishing DTCs (both waves) and ORCs (second wave only) in or near existing health facilities, rather than being driven by placement near areas of epidemiological need and in more remote areas.

Decision-making was driven by the humanitarian need to integrate services due to a lack of human resources and functioning health centers. Despite the rapid scale of infection, technical guidance with attention to high-risk groups like pregnant women and children with severe acute malnutrition were provided with delay. Finally, there was limited focus on community-based approaches to treatment, referral and surveillance.

The water, sanitation and hygiene (WASH) sector was unprepared to transition from generalized development-style programming to choleraspecific activities. It was not until September 2017, after the peak of the second wave, that targeted, outbreak-specific rapid response teams (RRTs) were established, operationalized, and managed at the level of the 22 governorates, leading to specific WASH activities to reduce transmission. A late 2017/ early 2018 evaluation by the WASH cluster found that the majority of beneficiaries were reached through system support, including fuel, operations and maintenance support, rehabilitation, and sewage treatment plant support as opposed to choleraspecific interventions.

The use of the oral cholera vaccine (OCV) was slowed by the lack of cholera response planning and technical knowledge among the Ministry of Public Health and Population (MoPHP) and partners.

The lack of an updated cholera preparedness and response plan meant that OCV was not integrated into the response mindset and thus, there was a lack of technical knowledge and familiarly with OCV. OCV was not sufficiently discussed during the first wave, and was requested then rejected by the MoPHP during the second wave based on differing conceptions of the overall scale of distribution. The March 2018 plan is the first document that mentions an OCV strategy, based on a January 2018 risk assessment. The MoPHP then made a successful request to the Global Task Force for Cholera Control in April 2018 for 4.6 million doses for preventative use against future surges of cholera.

• Three coordination systems operated with various success and limited complementarity. These included the health and WASH clusters and a Cholera Task Force (CTF) and followed by the implementation of the incident management system (IMS) and emergency operations centers (EOCs) led by WHO.

Coordination was also hampered by having two different governments in Yemen and political tensions.

• Insecurity and airstrikes resulted in extensive damage to civilian infrastructure, including water systems. It likely contributed to service disruptions, reduced access to many areas of the country, and potentially increased cholera transmission. Other stressors included the closures of ports, airports and blockades of imported food, fuel, medications and medical supplies, and persistent ground-level insecurity.

CONCLUSIONS:

The cholera response in Yemen was and remains extremely complicated and challenging for a variety of political, security, cultural, and environmental reasons. The study team recognizes these challenges and commends the government, international and national organizations, and the donors for working to find solutions in such a difficult context. There are no easy fixes to these challenges, and the conclusions and recommendations are meant to be constructive and practical, taking into account the extreme limitations of working in Yemen during an active conflict.

The findings were consistent across respondents and methods. The study team found that several areas gained strength throughout the second wave, including: an extensive operational footprint which reached into insecure areas; the strengthening of the collaborations between WHO and UNICEF and the health and WASH clusters; the initiation of a funding mechanism through the World Bank which enabled a timely response at scale; the revitalization of the WASH strategy; and, eventual consensus and use of OCV.

Conversely, the major gaps of this response are rooted in weaknesses in preparedness and the early strategies developed in the first wave. An after-action review after the first wave could have institutionalized these areas in order to prevent a much larger second wave.

The World Bank’s commitment to the cholera response provides the rationale for major investment in bolstering the preparedness activities in Yemen and other conflictaffected contexts which would go far for addressing the foundational gaps discussed in this case study.

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Cholera in Yemen: a case study of epidemic preparedness and response

The main objective of this report was to identify lessons learned from the preparedness and detection phase to the end of second wave of the cholera epidemic in Yemen to better prepare for future outbreaks in Yemen and similar contexts.

In 2015, the United Nations declared Yemen a Level 3 emergency. On September 28, 2016, a large-scale cholera outbreak began. Between April 27, 2017 and July 1, 2018, more than one million suspected cases in two waves were reported. In the last decade, several large-scale and high-mortality cholera outbreaks have occurred during complex humanitarian emergencies including in Iraq, Somalia, and South Sudan. While the issues of “what to do” to control cholera are largely known, context-specific practices on “how to do it” in order to surmount challenges to coordination, logistics, insecurity, access, and politics, remain needed. During the Yemen cholera outbreak response, questions arose on how to effectively respond to a cholera outbreak at a national scale during an existing emergency. 

Document links last validated on: 23 December 2019

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By Emily Anthes

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