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
Journal Article > ReviewFull Text
Lancet Infect Dis. 2021 March 1; Volume 21 (Issue 3); e37-e48.; DOI:10.1016/S1473-3099(20)30479-5
Ratnayake R, Finger F, Azman AS, Lantagne D, Funk S, et al.
Lancet Infect Dis. 2021 March 1; Volume 21 (Issue 3); e37-e48.; DOI:10.1016/S1473-3099(20)30479-5
Globally, cholera epidemics continue to challenge disease control. Although mass campaigns covering large populations are commonly used to control cholera, spatial targeting of case households and their radius is emerging as a potentially efficient strategy. We did a Scoping Review to investigate the effectiveness of interventions delivered through case-area targeted intervention, its optimal spatiotemporal scale, and its effectiveness in reducing transmission. 53 articles were retrieved. We found that antibiotic chemoprophylaxis, point-of-use water treatment, and hygiene promotion can rapidly reduce household transmission, and single-dose vaccination can extend the duration of protection within the radius of households. Evidence supports a high-risk spatiotemporal zone of 100 m around case households, for 7 days. Two evaluations separately showed reductions in household transmission when targeting case households, and in size and duration of case clusters when targeting radii. Although case-area targeted intervention shows promise for outbreak control, it is critically dependent on early detection capacity and requires prospective evaluation of intervention packages.
Journal Article > Short ReportFull Text
Emerg Infect Dis. 2024 August 1; Volume 30 (Issue 8); 1677-1682.; DOI:10.3201/eid3008.231137
Ratnayake R, Knee J, Cumming O, Saidi JM, Rumedeka BB, et al.
Emerg Infect Dis. 2024 August 1; Volume 30 (Issue 8); 1677-1682.; DOI:10.3201/eid3008.231137
We evaluated the spatiotemporal clustering of rapid diagnostic test−positive cholera cases in Uvira, eastern Democratic Republic of the Congo. We detected spatiotemporal clusters that consistently overlapped with major rivers, and we outlined the extent of zones of increased risk that are compatible with the radii currently used for targeted interventions.
Journal Article > CommentaryFull Text
Lancet Diabetes Endocrinol. 2019 August 1; DOI:10.1016/S2213-8587(19)30197-4.
Kehlenbrink S, Jaacks LM, Perone SA, Ansbro É, Ashbourne E, et al.
Lancet Diabetes Endocrinol. 2019 August 1; DOI:10.1016/S2213-8587(19)30197-4.
Journal Article > ResearchFull Text
Confl Health. 2020 November 25; Volume 14; 80.; DOI:10.1186/s13031-020-00325-6
Garry S, Abdelmagid N, Baxter LM, Roberts N, de Waroux OL, et al.
Confl Health. 2020 November 25; Volume 14; 80.; DOI:10.1186/s13031-020-00325-6
The COVID-19 pandemic has the potential to cause high morbidity and mortality in crisis-affected populations. Delivering COVID-19 treatment services in crisis settings will likely entail complex trade-offs between offering services of clinical benefit and minimising risks of nosocomial infection, while allocating resources appropriately and safeguarding other essential services. This paper outlines considerations for humanitarian actors planning COVID-19 treatment services where vaccination is not yet widely available. We suggest key decision-making considerations: allocation of resources to COVID-19 treatment services and the design of clinical services should be based on community preferences, likely opportunity costs, and a clearly articulated package of care across different health system levels. Moreover, appropriate service planning requires information on the expected COVID-19 burden and the resilience of the health system. We explore COVID-19 treatment service options at the patient level (diagnosis, management, location and level of treatment) and measures to reduce nosocomial transmission (cohorting patients, protecting healthcare workers). Lastly, we propose key indicators for monitoring COVID-19 health services.
Journal Article > Case Report/SeriesFull Text
Bull World Health Organ. 2023 March 1; Volume 101 (Issue 03); 170-178.; DOI:10.2471/BLT.22.288885
Ouamba JP, Fouda Mbarga N, Ciglenecki I, Ratnayake R, Tchiasso D, et al.
Bull World Health Organ. 2023 March 1; Volume 101 (Issue 03); 170-178.; DOI:10.2471/BLT.22.288885
English
Français
Español
عَرَبِيّ
中文
Русский
OBJECTIVE
To describe the implementation of case-area targeted interventions to reduce cholera transmission using a rapid, localized response in Kribi district, Cameroon.
METHODS
We used a cross-sectional design to study the implementation of case-area targeted interventions. We initiated interventions after rapid diagnostic test confirmation of a case of cholera. We targeted households within a 100-250 metre perimeter around the index case (spatial targeting). The interventions package included: health promotion, oral cholera vaccination, antibiotic chemoprophylaxis for nonimmunized direct contacts, point-of-use water treatment and active case-finding.
FINDINGS
We implemented eight targeted intervention packages in four health areas of Kribi between 17 September 2020 and 16 October 2020. We visited 1533 households (range: 7-544 per case-area) hosting 5877 individuals (range: 7-1687 per case-area). The average time from detection of the index case to implementation of interventions was 3.4 days (range: 1-7). Oral cholera vaccination increased overall immunization coverage in Kribi from 49.2% (2771/5621 people) to 79.3% (4456/5621 people). Interventions also led to the detection and prompt management of eight suspected cases of cholera, five of whom had severe dehydration. Stool culture was positive for Vibrio cholerae O1 in four cases. The average time from onset of symptoms to admission of a person with cholera to a health facility was 1.2 days.
CONCLUSION
Despite challenges, we successfully implemented targeted interventions at the tail-end of a cholera epidemic, after which no further cases were reported in Kribi up until week 49 of 2021. The effectiveness of case-area targeted interventions in stopping or reducing cholera transmission needs further investigation.
To describe the implementation of case-area targeted interventions to reduce cholera transmission using a rapid, localized response in Kribi district, Cameroon.
METHODS
We used a cross-sectional design to study the implementation of case-area targeted interventions. We initiated interventions after rapid diagnostic test confirmation of a case of cholera. We targeted households within a 100-250 metre perimeter around the index case (spatial targeting). The interventions package included: health promotion, oral cholera vaccination, antibiotic chemoprophylaxis for nonimmunized direct contacts, point-of-use water treatment and active case-finding.
FINDINGS
We implemented eight targeted intervention packages in four health areas of Kribi between 17 September 2020 and 16 October 2020. We visited 1533 households (range: 7-544 per case-area) hosting 5877 individuals (range: 7-1687 per case-area). The average time from detection of the index case to implementation of interventions was 3.4 days (range: 1-7). Oral cholera vaccination increased overall immunization coverage in Kribi from 49.2% (2771/5621 people) to 79.3% (4456/5621 people). Interventions also led to the detection and prompt management of eight suspected cases of cholera, five of whom had severe dehydration. Stool culture was positive for Vibrio cholerae O1 in four cases. The average time from onset of symptoms to admission of a person with cholera to a health facility was 1.2 days.
CONCLUSION
Despite challenges, we successfully implemented targeted interventions at the tail-end of a cholera epidemic, after which no further cases were reported in Kribi up until week 49 of 2021. The effectiveness of case-area targeted interventions in stopping or reducing cholera transmission needs further investigation.
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 > Poster
Ouamba JP, Peyraud N, Mbarga NF, Ciglenecki I, Finger F, et al.
MSF Scientific Days International 2021: Research. 2021 May 18
Journal Article > ReviewFull Text
Lancet Diabetes Endocrinol. 2019 March 13; Volume 7 (Issue 8); 638-647.; DOI:10.1016/S2213-8587(19)30082-8
Kehlenbrink S, Smith JS, Ansbro É, Fuhr D, Cheung ATL, et al.
Lancet Diabetes Endocrinol. 2019 March 13; Volume 7 (Issue 8); 638-647.; DOI:10.1016/S2213-8587(19)30082-8
Human suffering as a result of natural disasters or conflict includes death and disability from non-communicable diseases, including diabetes, which have largely been neglected in humanitarian crises. The objectives of this Series paper were to examine the evidence on the burden of diabetes, use of health services, and access to care for people with diabetes among populations affected by humanitarian crises in low-income and middle-income countries, and to identify research gaps for future studies. We reviewed the scientific literature on this topic published between 1992 and 2018. The results emphasise that the burden of diabetes in humanitarian settings is not being captured, clinical guidance is insufficient, and diabetes is not being adequately addressed. Crisis-affected populations with diabetes face enormous constraints accessing care, mainly because of high medical costs. Further research is needed to characterise the epidemiology of diabetes in humanitarian settings and to develop simplified, cost-effective models of care to improve the delivery of diabetes care during humanitarian crises.
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.