Conference Material > Slide Presentation
Finger F, Mimbu N, Ratnayake R, Meakin S, Bahati JB, et al.
MSF Scientific Day International 2024. 2024 May 16; DOI:10.57740/tC1av3293
Conference Material > Video
Mimbu N, Finger F
Epicentre Scientific Day Paris 2023. 2023 June 8
English
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Conference Material > Abstract
Mimbu N, Finger F
Epicentre Scientific Day Paris 2023. 2023 June 8
The risk of small-scale cholera outbreaks propagating rapidly and enlarging extensively remains substantial. As opposed to relying on mass, community-wide approaches, cholera control strategies could focus on proactively containing the first clusters. Case-area targeted interventions (CATI) are based on the premise that early detection can trigger a rapid, localised response in the high-risk radius around one or several case-households to reduce transmission sufficiently to extinguish the outbreak or reduce its spread. Current evidence supports a high-risk spatiotemporal zone of 100 to 250 meters around case-households for 7 days.
The CATI package delivered by Médecins Sans Frontières (MSF) incorporates key transmission-reducing interventions (including household-level water, sanitation,
and hygiene measures, health promotion, active case-finding, antibiotic chemoprophylaxis, and, single-dose oral cholera vaccination (OCV)). We present the first results of an observational study designed to evaluate the CATI strategy applied by MSF. In addition to effectiveness, our study measures the feasibility, resource requirements, and process of implementing this approach.
During the study period, CATI has been implemented by 4 MSF operational sections in 118 rings in 5 different sites in the Democratic Republic of the Congo. The median number of households in each ring was 69. The median administrative vaccination coverage achieved was 89% across all sites. The median delay to CATI implementation was of 2 days from the onset of symptoms of the primary case, and the delay to vaccination was 3.5 days. The characteristics of the CATI rings varied widely across sites and between individual rings. The number of secondary cases observed in rings was generally low, no secondary case was observed in overs 75% of all rings.
Preliminary results show that rapidly implementing CATI with vaccination to contain cholera cases is feasible and that the coverage of the different interventions is satisfactory. A more detailed analysis of effectiveness, coverage and resource needs is underway.
KEY MESSAGE
Case-Area Targeted Interventions aim to rapidly deliver a package of public health interventions to people living in the high-risk areas surrounding reported cholera cases. Here we present the first results of an observational study designed to evaluate the feasibility and effectiveness of CATI implemented in the DRC by MSF.
Thia abstract is not to be quoted for publication
The CATI package delivered by Médecins Sans Frontières (MSF) incorporates key transmission-reducing interventions (including household-level water, sanitation,
and hygiene measures, health promotion, active case-finding, antibiotic chemoprophylaxis, and, single-dose oral cholera vaccination (OCV)). We present the first results of an observational study designed to evaluate the CATI strategy applied by MSF. In addition to effectiveness, our study measures the feasibility, resource requirements, and process of implementing this approach.
During the study period, CATI has been implemented by 4 MSF operational sections in 118 rings in 5 different sites in the Democratic Republic of the Congo. The median number of households in each ring was 69. The median administrative vaccination coverage achieved was 89% across all sites. The median delay to CATI implementation was of 2 days from the onset of symptoms of the primary case, and the delay to vaccination was 3.5 days. The characteristics of the CATI rings varied widely across sites and between individual rings. The number of secondary cases observed in rings was generally low, no secondary case was observed in overs 75% of all rings.
Preliminary results show that rapidly implementing CATI with vaccination to contain cholera cases is feasible and that the coverage of the different interventions is satisfactory. A more detailed analysis of effectiveness, coverage and resource needs is underway.
KEY MESSAGE
Case-Area Targeted Interventions aim to rapidly deliver a package of public health interventions to people living in the high-risk areas surrounding reported cholera cases. Here we present the first results of an observational study designed to evaluate the feasibility and effectiveness of CATI implemented in the DRC by MSF.
Thia abstract is not to be quoted for publication
Protocol > Research Study
BMJ Open. 2022 July 6; Volume 12 (Issue 7); e061206.; DOI:10.1136/bmjopen-2022-061206
Ratnayake R, Peyraud N, Ciglenecki I, Gignoux EM, Lightowler M, et al.
BMJ Open. 2022 July 6; Volume 12 (Issue 7); e061206.; DOI:10.1136/bmjopen-2022-061206
INTRODUCTION
Cholera outbreaks in fragile settings are prone to rapid expansion. Case-area targeted interventions (CATIs) have been proposed as a rapid and efficient response strategy to halt or substantially reduce the size of small outbreaks. CATI aims to deliver synergistic interventions (eg, water, sanitation, and hygiene interventions, vaccination, and antibiotic chemoprophylaxis) to households in a 100-250 m 'ring' around primary outbreak cases.
METHODS AND ANALYSIS
We report on a protocol for a prospective observational study of the effectiveness of CATI. Médecins Sans Frontières (MSF) plans to implement CATI in the Democratic Republic of the Congo (DRC), Cameroon, Niger and Zimbabwe. This study will run in parallel to each implementation. The primary outcome is the cumulative incidence of cholera in each CATI ring. CATI will be triggered immediately on notification of a case in a new area. As with most real-world interventions, there will be delays to response as the strategy is rolled out. We will compare the cumulative incidence among rings as a function of response delay, as a proxy for performance. Cross-sectional household surveys will measure population-based coverage. Cohort studies will measure effects on reducing incidence among household contacts and changes in antimicrobial resistance.
ETHICS AND DISSEMINATION
The ethics review boards of MSF and the London School of Hygiene and Tropical Medicine have approved a generic protocol. The DRC and Niger-specific versions have been approved by the respective national ethics review boards. Approvals are in process for Cameroon and Zimbabwe. The study findings will be disseminated to the networks of national cholera control actors and the Global Task Force for Cholera Control using meetings and policy briefs, to the scientific community using journal articles, and to communities via community meetings.
Cholera outbreaks in fragile settings are prone to rapid expansion. Case-area targeted interventions (CATIs) have been proposed as a rapid and efficient response strategy to halt or substantially reduce the size of small outbreaks. CATI aims to deliver synergistic interventions (eg, water, sanitation, and hygiene interventions, vaccination, and antibiotic chemoprophylaxis) to households in a 100-250 m 'ring' around primary outbreak cases.
METHODS AND ANALYSIS
We report on a protocol for a prospective observational study of the effectiveness of CATI. Médecins Sans Frontières (MSF) plans to implement CATI in the Democratic Republic of the Congo (DRC), Cameroon, Niger and Zimbabwe. This study will run in parallel to each implementation. The primary outcome is the cumulative incidence of cholera in each CATI ring. CATI will be triggered immediately on notification of a case in a new area. As with most real-world interventions, there will be delays to response as the strategy is rolled out. We will compare the cumulative incidence among rings as a function of response delay, as a proxy for performance. Cross-sectional household surveys will measure population-based coverage. Cohort studies will measure effects on reducing incidence among household contacts and changes in antimicrobial resistance.
ETHICS AND DISSEMINATION
The ethics review boards of MSF and the London School of Hygiene and Tropical Medicine have approved a generic protocol. The DRC and Niger-specific versions have been approved by the respective national ethics review boards. Approvals are in process for Cameroon and Zimbabwe. The study findings will be disseminated to the networks of national cholera control actors and the Global Task Force for Cholera Control using meetings and policy briefs, to the scientific community using journal articles, and to communities via community meetings.
Conference Material > Abstract
Finger F, Mimbu N, Ratnayake R, Meakin S, Bahati JB, et al.
MSF Scientific Day International 2024. 2024 May 16; DOI:10.57740/hfok99y
INTRODUCTION
The risk of cholera outbreaks spreading rapidly and extensively is substantial. Case-area targeted interventions (CATI) are based on the premise that early detection can trigger a rapid, localised response in the high-risk radius around case-households to reduce transmission sufficiently to extinguish the outbreak or reduce its spread, as opposed to relying on resource-intensive mass interventions. Current evidence supports intervention in a high-risk spatiotemporal zone of up to 200 m around case- households for 5 days after case presentation. Médecins Sans Frontières (MSF) started delivering CATI to people living within these high-risk rings during outbreaks in the Democratic Republic of the Congo in April 2022. We present the results of a prospective observational study designed to evaluate the CATI strategy, measuring effectiveness, feasibility, timeliness, and resource requirements, and we extract operational learnings.
METHODS
Between April 2022 and April 2023, MSF delivered the holistic CATI package in five cholera-affected regions. The package incorporated key interventions combining household-level water, sanitation, and hygiene measures, health promotion, antibiotic chemoprophylaxis, and single-dose oral cholera vaccination (OCV). We conducted a survey in each ring roughly 3 weeks after the intervention to estimate coverage and uptake of the different components. We measured effectiveness by comparing cholera incidence in the first 30 days between rings with different delays from primary case presentation to CATI implementation, using a Bayesian regression model and adjusting for covariates such as population density, age, and access to water and sanitation.
RESULTS
During the study, four MSF operational sections implemented 118 CATI rings in five sites. The median number of households per ring was 70, the median OCV coverage was 85%, and the median time from presentation of the primary case to CATI implementation and to vaccination was 2 days and 3 days, respectively. These characteristics varied widely across sites and between rings. No secondary cases were observed in 81 (78%) of 104 rings included in the analysis, and we noted a (non- significant) decreasing trend in the number of secondary cases with decreasing delay to CATI implementation, e.g. 1.3 cases [95% CrI 0.01–4.9] for CATI implementation starting within 5 days from primary case presentation, and 0.5 cases [0.03–2.0] for CATI starting within 2 days.
CONCLUSION
Our results show that rapid implementation of CATI with vaccination is feasible in complex contexts. The number of secondary cases was low when CATI was implemented promptly. This highly targeted approach may be an effective strategy to quickly protect people most at risk and is resource- efficient if implemented early to extinguish localised outbreaks before they require mass interventions.
The risk of cholera outbreaks spreading rapidly and extensively is substantial. Case-area targeted interventions (CATI) are based on the premise that early detection can trigger a rapid, localised response in the high-risk radius around case-households to reduce transmission sufficiently to extinguish the outbreak or reduce its spread, as opposed to relying on resource-intensive mass interventions. Current evidence supports intervention in a high-risk spatiotemporal zone of up to 200 m around case- households for 5 days after case presentation. Médecins Sans Frontières (MSF) started delivering CATI to people living within these high-risk rings during outbreaks in the Democratic Republic of the Congo in April 2022. We present the results of a prospective observational study designed to evaluate the CATI strategy, measuring effectiveness, feasibility, timeliness, and resource requirements, and we extract operational learnings.
METHODS
Between April 2022 and April 2023, MSF delivered the holistic CATI package in five cholera-affected regions. The package incorporated key interventions combining household-level water, sanitation, and hygiene measures, health promotion, antibiotic chemoprophylaxis, and single-dose oral cholera vaccination (OCV). We conducted a survey in each ring roughly 3 weeks after the intervention to estimate coverage and uptake of the different components. We measured effectiveness by comparing cholera incidence in the first 30 days between rings with different delays from primary case presentation to CATI implementation, using a Bayesian regression model and adjusting for covariates such as population density, age, and access to water and sanitation.
RESULTS
During the study, four MSF operational sections implemented 118 CATI rings in five sites. The median number of households per ring was 70, the median OCV coverage was 85%, and the median time from presentation of the primary case to CATI implementation and to vaccination was 2 days and 3 days, respectively. These characteristics varied widely across sites and between rings. No secondary cases were observed in 81 (78%) of 104 rings included in the analysis, and we noted a (non- significant) decreasing trend in the number of secondary cases with decreasing delay to CATI implementation, e.g. 1.3 cases [95% CrI 0.01–4.9] for CATI implementation starting within 5 days from primary case presentation, and 0.5 cases [0.03–2.0] for CATI starting within 2 days.
CONCLUSION
Our results show that rapid implementation of CATI with vaccination is feasible in complex contexts. The number of secondary cases was low when CATI was implemented promptly. This highly targeted approach may be an effective strategy to quickly protect people most at risk and is resource- efficient if implemented early to extinguish localised outbreaks before they require mass interventions.
Conference Material > Poster
Moser W, Broban A, Welo PO, Mukadi D, Gerstl S, et al.
Epicentre Scientific Day 2024. 2024 May 23