{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T08:14:45Z","timestamp":1782202485957,"version":"3.54.5"},"reference-count":56,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2025,9,23]],"date-time":"2025-09-23T00:00:00Z","timestamp":1758585600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosntds.org"],"crossmark-restriction":false},"short-container-title":["PLoS Negl Trop Dis"],"abstract":"<jats:p>Cholera, a severe fecal-oral disease, disproportionately affects the poorest communities who lack access to safe water and sanitation. Individuals living in the same household, or within a few hundred meters, of a patient are at increased risk of infection. Thus, during cholera outbreaks, targeted response strategies, such as case-area targeted interventions (CATIs), provide health (e.g., vaccination and antibiotic prophylaxis) and water, sanitation, and hygiene services for affected households and at-risk neighbors living in a defined ring. Previous research on CATIs has focused on impact and effectiveness, and less on implementation processes. As cholera outbreaks occur in diverse settings with differentiated challenges, we investigated how CATI and CATI-like mechanisms can be best used and adapted. Drawing on 43 peer-reviewed articles and gray literature sources retrieved through a narrative review, and 15 key informant interviews conducted using a snowball sampling approach, we identified 27 CATI or CATI-like experiences across 15 countries in Africa, Asia, the Caribbean, and Middle East between 2004 and 2024. Four delivery mechanisms were identified: CATI, pre-CATI, case-cluster, and health-facility-based interventions (HBI). Challenges to implementation included: delays in response; difficulty accessing populations; resource shortages to initiate, maintain, or scale up response; overwhelmed response capacity; limited skills and knowledge; low uptake and acceptance; weak coordination; poor reporting and monitoring; and sustainability concerns. Implementers adapted delivery to overcome challenges, particularly in outbreaks with high case-loads and in insecure and hard-to-reach contexts by ensuring readiness and early activation, strengthening local actors\u2019 capacity, optimizing resources, adjusting ring sizes, and prioritizing cases. Based on these results, we developed a practitioner-centered framework to optimize programmatic implementation through context-specific delivery mechanism and ultimately decrease cholera incidence.<\/jats:p>","DOI":"10.1371\/journal.pntd.0013534","type":"journal-article","created":{"date-parts":[[2025,9,23]],"date-time":"2025-09-23T17:44:24Z","timestamp":1758649464000},"page":"e0013534","update-policy":"https:\/\/doi.org\/10.1371\/journal.pntd.corrections_policy","source":"Crossref","is-referenced-by-count":2,"title":["Optimizing the implementation of case-area targeted interventions during cholera outbreaks with context-specific delivery mechanisms"],"prefix":"10.1371","volume":"19","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-8311-4705","authenticated-orcid":true,"given":"Jessica","family":"Dunoyer","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruwan","family":"Ratnayake","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandy","family":"Moore","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gregory","family":"Bulit","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samuel","family":"Beaulieu","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christophe","family":"Valingot","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pierre-Yves","family":"Oger","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bertrand","family":"Sudre","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniele","family":"Lantagne","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicola","family":"Desmond","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2025,9,23]]},"reference":[{"issue":"6","key":"pntd.0013534.ref001","article-title":"Updated global burden of cholera in endemic countries","volume":"9","author":"M Ali","year":"2015","journal-title":"PLoS Negl Trop Dis"},{"issue":"10133","key":"pntd.0013534.ref002","doi-asserted-by":"crossref","first-page":"1908","DOI":"10.1016\/S0140-6736(17)33050-7","article-title":"Mapping the burden of cholera in sub-Saharan Africa and implications for control: an analysis of data across geographical scales","volume":"391","author":"J Lessler","year":"2018","journal-title":"Lancet"},{"key":"pntd.0013534.ref003","unstructured":"GTFCC. Ending Cholera - A Global Roadmap to 2030. 2017."},{"key":"pntd.0013534.ref004","unstructured":"WHO, JMP, UNICEF. JMP Progress on Drinking Water, Sanitation and Hygiene: 2022 Update and SDG Baselines. [Internet]. 2022 [cited 2024 Apr 23]. Available from: https:\/\/washdata.org\/data\/household#!\/dashboard\/new"},{"key":"pntd.0013534.ref005","unstructured":"WHO. Multi-country outbreak of cholera [Internet]. 2025. Available from: https:\/\/www.who.int\/publications\/m\/item\/multi-country-cholera-outbreak--external-situation-report--22---24-january-2025#:~:text=Overview,those%20reported%20in%20December%202023"},{"issue":"6","key":"pntd.0013534.ref006","first-page":"2134","article-title":"Cholera cases cluster in time and space in Matlab, Bangladesh: implications for targeted preventive interventions","volume":"45","author":"AK Debes","year":"2016","journal-title":"Int J Epidemiol"},{"issue":"2","key":"pntd.0013534.ref007","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pmed.1002509","article-title":"The potential impact of case-area targeted interventions in response to cholera outbreaks: A modeling study","volume":"15","author":"F Finger","year":"2018","journal-title":"PLoS Med"},{"issue":"3","key":"pntd.0013534.ref008","doi-asserted-by":"crossref","DOI":"10.1016\/S1473-3099(20)30479-5","article-title":"Highly targeted spatiotemporal interventions against cholera epidemics, 2000-19: a scoping review","volume":"21","author":"R Ratnayake","year":"2021","journal-title":"Lancet Infect Dis"},{"key":"pntd.0013534.ref009","doi-asserted-by":"crossref","unstructured":"Ratnayake R., Knee J., Cumming O., Saidi J.M., Rumedeka B.B., Finger F., et al. Spatiotemporal modelling of cholera and implications for its control, Uvira, Democratic Republic of the Congo. medRxiv [Internet]. 2023;((Ratnayake, Knee, Cumming, Edmunds, Checchi, Gallandat) London School of Hygiene and Tropical Medicine, London, United Kingdom). 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Evaluation of the UNICEF Level 3 response to the cholera epidemic in Yemen: crisis within a crisis: executive summary [Internet]. 2018. Available from: https:\/\/digitallibrary.un.org\/record\/1637498?ln=fr&v=pdf"},{"key":"pntd.0013534.ref041","article-title":"First wave of the 2016-17 cholera outbreak in Hodeidah City, Yemen - ACF experience and lessons learned","author":"M Altmann","year":"2017","journal-title":"PLoS Curr"},{"key":"pntd.0013534.ref042","unstructured":"Bulit G. Cholera rapid response teams activation in Harare, Zimbabwe [Internet]. UNICEF. 2018. 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First inter CO learning exchange on cholera preparedness and response in communities. 2023."},{"key":"pntd.0013534.ref046","unstructured":"UNICEF ESARO. Second inter CO learning exchange on cholera preparedness and response in communities. 2023."},{"issue":"3","key":"pntd.0013534.ref047","doi-asserted-by":"crossref","first-page":"611","DOI":"10.4269\/ajtmh.20-1314","article-title":"Household Disinfection Interventions to Prevent Cholera Transmission: Facilitators, Barriers, Training, and Evidence Needs","volume":"105","author":"C Heylen","year":"2021","journal-title":"Am J Trop Med Hyg"},{"issue":"19","key":"pntd.0013534.ref048","doi-asserted-by":"crossref","first-page":"12905","DOI":"10.3390\/ijerph191912905","article-title":"Randomized Controlled Trial of the Cholera-Hospital-Based-Intervention-for-7-Days (CHoBI7) Cholera Rapid Response Program to Reduce Diarrheal Diseases in Bangladesh","volume":"19","author":"CM George","year":"2022","journal-title":"Int J Environ Res Public Health"},{"issue":"6","key":"pntd.0013534.ref049","article-title":"Promotion of cholera awareness among households of cholera patients: a randomized controlled trial of the cholera-hospital-based-intervention-for-7 days (CHoBI7) intervention","volume":"95","author":"KM Saif-Ur-Rahman","year":"2016","journal-title":"Am Soc Trop Med Hyg"},{"issue":"20","key":"pntd.0013534.ref050","doi-asserted-by":"crossref","first-page":"13352","DOI":"10.3390\/ijerph192013352","article-title":"Formative Research for the Development of the CHoBI7 Cholera Rapid Response Program for Cholera Hotspots in Bangladesh","volume":"19","author":"F Zohura","year":"2022","journal-title":"Int J Environ Res Public Health"},{"issue":"1","key":"pntd.0013534.ref051","doi-asserted-by":"crossref","first-page":"12","DOI":"10.1186\/s13031-022-00445-1","article-title":"Identifying transferable lessons from cholera epidemic responses by M\u00e9decins Sans Fronti\u00e8res in Mozambique, Malawi and the Democratic Republic of Congo, 2015-2018: a scoping review","volume":"16","author":"L D\u2019Mello-Guyett","year":"2022","journal-title":"Confl Health"},{"key":"pntd.0013534.ref052","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1186\/s13031-020-00294-w","article-title":"Distribution of hygiene kits during a cholera outbreak in Kasa\u00ef-Oriental, Democratic Republic of Congo: a process evaluation","volume":"14","author":"L D\u2019Mello-Guyett","year":"2020","journal-title":"Confl Health"},{"issue":"8","key":"pntd.0013534.ref053","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pntd.0008661","article-title":"Household spraying in cholera outbreaks: Insights from three exploratory, mixed-methods field effectiveness evaluations","volume":"14","author":"K Gallandat","year":"2020","journal-title":"PLoS Negl Trop Dis"},{"issue":"1","key":"pntd.0013534.ref054","doi-asserted-by":"crossref","first-page":"397","DOI":"10.1186\/s12916-020-01865-7","article-title":"Early detection of cholera epidemics to support control in fragile states: estimation of delays and potential epidemic sizes","volume":"18","author":"R Ratnayake","year":"2020","journal-title":"BMC Med"},{"key":"pntd.0013534.ref055","unstructured":"Health and WASH Sector North-East Nigeria. Cholera: Joint WASH and Health Sectors Review Meeting Report. 2024."},{"key":"pntd.0013534.ref056","unstructured":"Haitians Flee a Nation Nearing Collapse [Internet]. Reliefweb; 2023. 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