During cholera outbreaks, quickly reaching affected households and nearby neighbors is key to stopping transmission. A recent study sheds light on how to deploy and adapt targeted mechanisms in real-world conditions, offering practical ways to strengthen and accelerate responses in challenging contexts.
Cholera is a severe disease disproportionately affecting poor communities, with individuals near patients at higher risk of infection. During outbreaks, case-area targeted interventions (CATIs) provide health and WASH (water, sanitation, and hygiene) services to affected households and at-risk neighbors within a defined area. A recent study by Dunoyer et al. has investigated how CATI and CATI-like mechanisms can be effectively deployed and adapted across various contexts to inform technical guidance and optimize implementation (1).
Across 15 countries, the study identified four distinct delivery mechanisms:
- Standard CATI: mobile teams promptly delivering a multi-sectoral package of interventions to case households and at-risk neighbors within a defined ring.
- Pre-CATI: a set of interventions delivered to case households and at-risk neighbors by community volunteers trained to respond immediately upon case detection.
- Case-cluster interventions: tailored interventions delivered within geographic clusters of cases.
- Health facility-based interventions: cholera patients receive supplies and hygiene education at treatment facilities.
The study found that most interventions focused solely on WASH components such as household disinfection, hygiene promotion, and point-of-use water treatment. Only 37% incorporated health components such as vaccination or antibiotic prophylaxis. Targeted interventions were conducted in both urban and rural areas. Interventions were carried out in a variety of contexts, including conflict settings, densely populated areas, remote locations, slums, and camps (1).
The analysis revealed several implementation challenges, most notably: a lack of resources, delays in response activation, limited skills and knowledge, difficulties accessing case-households, and an overwhelmed response capacity. During periods of high caseload, standard CATIs were resource-intensive and difficult to scale. In remote or conflict-affected areas, deployment delays significantly reduced effectiveness (1).
To address these challenges, implementers developed numerous adaptations (1):
- Establishing CATI-like delivery mechanisms in challenging contexts (e.g., pre-CATIs, case-cluster, and health facility-based interventions)
- Ensuring readiness, early detection, and rapid activation
- Prioritizing cases using rapid diagnostic tests or severity criteria
- Adjusting ring sizes based on population density and caseload
- Optimizing resources (e.g., integration of CATI teams across sectors to reduce duplication, distribution of supplies directly through health facilities)
- Engaging community leaders to increase acceptance
- Strengthening the capacity of local actors
- Ensuring regular monitoring and reporting
The authors developed a practitioner-centered implementation framework for each delivery mechanism. The study recommends case-cluster approaches and/or health facility-based interventions in contexts with high caseloads in dense urban areas. Meanwhile, the authors recommend the pre-CATI approach with community-based networks in remote or conflict-affected settings. The authors emphasize that the CATI strategy should be integrated into comprehensive cholera control strategies rather than viewed as a standalone solution, and call for the development of operational guidelines that address context-specific implementation challenges and the selection of delivery mechanisms (1).
1. Dunoyer J, Ratnayake R, Moore S, Bulit G, Beaulieu S, Valingot C, et al. Optimizing the implementation of case-area targeted interventions during cholera outbreaks with context-specific delivery mechanisms. PLoS Negl Trop Dis. 2025 Sept;19(9):e0013534.
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