TY - JOUR
T1 - Case-area targeted interventions during a large-scale cholera epidemic
T2 - A prospective cohort study in Northeast Nigeria
AU - OKeeffe, Jennifer
AU - Salem-Bango, Lindsay
AU - Desjardins, Michael R.
AU - Lantagne, Daniele
AU - Altare, Chiara
AU - Kaur, Gurpreet
AU - Heath, Thomas
AU - Rangaiya, Kanaganathan
AU - Obroh, Patricia Oke Oghene
AU - Audu, Ahmadu
AU - Lecuyot, Baptiste
AU - Zoungrana, Timothée
AU - Ihemezue, Emmanuel Emeka
AU - Aye, Solomon
AU - Sikder, Mustafa
AU - Doocy, Shannon
AU - Wang, Qiulin
AU - Xiao, Melody
AU - Spiegel, Paul B.
N1 - Publisher Copyright:
© 2024 OKeeffe et al.
PY - 2024/5
Y1 - 2024/5
N2 - Background Cholera outbreaks are on the rise globally, with conflict-affected settings particularly at risk. Case-area targeted interventions (CATIs), a strategy whereby teams provide a package of interventions to case and neighboring households within a predefined “ring,” are increasingly employed in cholera responses. However, evidence on their ability to attenuate incidence is limited. Methods and findings We conducted a prospective observational cohort study in 3 conflict-affected states in Nigeria in 2021. Enumerators within rapid response teams observed CATI implementation during a cholera outbreak and collected data on household demographics; existing water, sanitation, and hygiene (WASH) infrastructure; and CATI interventions. Descriptive statistics showed that CATIs were delivered to 46,864 case and neighbor households, with 80.0% of cases and 33.5% of neighbors receiving all intended supplies and activities, in a context with operational challenges of population density, supply stock outs, and security constraints. We then applied prospective Poisson space-time scan statistics (STSS) across 3 models for each state: (1) an unadjusted model with case and population data; (2) an environmentally adjusted model adjusting for distance to cholera treatment centers and existing WASH infrastructure (improved water source, improved latrine, and handwashing station); and (3) a fully adjusted model adjusting for environmental and CATI variables (supply of Aquatabs and soap, hygiene promotion, bedding and latrine disinfection activities, ring coverage, and response timeliness). We ran the STSS each day of our study period to evaluate the space-time dynamics of the cholera outbreaks. Compared to the unadjusted model, significant cholera clustering was attenuated in the environmentally adjusted model (from 572 to 18 clusters) but there was still risk of cholera transmission. Two states still yielded significant clusters (range 8–10 total clusters, relative risk of 2.2–5.5, 16.6–19.9 day duration, including 11.1–56.8 cholera cases). Cholera clustering was completely attenuated in the fully adjusted model, with no significant anomalous clusters across time and space. Associated measures including quantity, relative risk, significance, likelihood of recurrence, size, and duration of clusters reinforced the results. Key limitations include selection bias, remote data monitoring, and the lack of a control group. Conclusions CATIs were associated with significant reductions in cholera clustering in Northeast Nigeria despite operational challenges. Our results provide a strong justification for rapid implementation and scale-up CATIs in cholera-response, particularly in conflict settings where WASH access is often limited.
AB - Background Cholera outbreaks are on the rise globally, with conflict-affected settings particularly at risk. Case-area targeted interventions (CATIs), a strategy whereby teams provide a package of interventions to case and neighboring households within a predefined “ring,” are increasingly employed in cholera responses. However, evidence on their ability to attenuate incidence is limited. Methods and findings We conducted a prospective observational cohort study in 3 conflict-affected states in Nigeria in 2021. Enumerators within rapid response teams observed CATI implementation during a cholera outbreak and collected data on household demographics; existing water, sanitation, and hygiene (WASH) infrastructure; and CATI interventions. Descriptive statistics showed that CATIs were delivered to 46,864 case and neighbor households, with 80.0% of cases and 33.5% of neighbors receiving all intended supplies and activities, in a context with operational challenges of population density, supply stock outs, and security constraints. We then applied prospective Poisson space-time scan statistics (STSS) across 3 models for each state: (1) an unadjusted model with case and population data; (2) an environmentally adjusted model adjusting for distance to cholera treatment centers and existing WASH infrastructure (improved water source, improved latrine, and handwashing station); and (3) a fully adjusted model adjusting for environmental and CATI variables (supply of Aquatabs and soap, hygiene promotion, bedding and latrine disinfection activities, ring coverage, and response timeliness). We ran the STSS each day of our study period to evaluate the space-time dynamics of the cholera outbreaks. Compared to the unadjusted model, significant cholera clustering was attenuated in the environmentally adjusted model (from 572 to 18 clusters) but there was still risk of cholera transmission. Two states still yielded significant clusters (range 8–10 total clusters, relative risk of 2.2–5.5, 16.6–19.9 day duration, including 11.1–56.8 cholera cases). Cholera clustering was completely attenuated in the fully adjusted model, with no significant anomalous clusters across time and space. Associated measures including quantity, relative risk, significance, likelihood of recurrence, size, and duration of clusters reinforced the results. Key limitations include selection bias, remote data monitoring, and the lack of a control group. Conclusions CATIs were associated with significant reductions in cholera clustering in Northeast Nigeria despite operational challenges. Our results provide a strong justification for rapid implementation and scale-up CATIs in cholera-response, particularly in conflict settings where WASH access is often limited.
UR - http://www.scopus.com/inward/record.url?scp=85193461698&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85193461698&partnerID=8YFLogxK
U2 - 10.1371/journal.pmed.1004404
DO - 10.1371/journal.pmed.1004404
M3 - Article
C2 - 38728366
AN - SCOPUS:85193461698
SN - 1549-1277
VL - 21
JO - PLoS medicine
JF - PLoS medicine
IS - 5
M1 - e1004404
ER -