Blake Alexandre, Walder Adam, Hanks Ephraim M, Welo Placide Okitayemba, Luquero Francisco, Bompangue Didier, Bharti Nita
Biology Department, Center for Infectious Disease Dynamics, Penn State University, University Park, Pennsylvania, United States of America.
Statistics Department, Center for Infectious Disease Dynamics, Penn State University, University Park, Pennsylvania, United States of America.
PLoS Negl Trop Dis. 2025 Feb 19;19(2):e0012867. doi: 10.1371/journal.pntd.0012867. eCollection 2025 Feb.
Cholera is a bacterial water-borne diarrheal disease transmitted via the fecal-oral route that causes high morbidity in sub-Saharan Africa and Asia. It is preventable with vaccination, and Water, Sanitation, and Hygiene (WASH) improvements. However, the impact of vaccination in endemic settings remains unclear. Cholera is endemic in the city of Kalemie, on the shore of Lake Tanganyika, in the Democratic Republic of Congo, where both seasonal mobility and the lake, a potential environmental reservoir, may promote transmission. Kalemie received a vaccination campaign and WASH improvements in 2013-2016. We assessed the impact of this intervention to inform future control strategies in endemic settings. We fit compartmental models considering seasonal mobility and environmentally-based transmission. We estimated the number of cases the intervention avoided, and the relative contributions of the elements promoting local cholera transmission. We estimated the intervention avoided 5,259 cases (95% credible interval: 1,576.6-11,337.8) over 118 weeks. Transmission did not rely on seasonal mobility and was primarily environmentally-driven. Removing environmental exposure or contamination could control local transmission. Repeated environmental exposure could maintain high population immunity and decrease the impact of vaccination in similar endemic areas. Addressing environmental exposure and contamination should be the primary target of interventions in such settings.
霍乱是一种通过粪口途径传播的细菌性水源性腹泻疾病，在撒哈拉以南非洲和亚洲导致高发病率。通过接种疫苗以及改善水、环境卫生和个人卫生（WASH）措施可预防该病。然而，在地方流行环境中接种疫苗的影响仍不明确。在刚果民主共和国坦噶尼喀湖岸边的卡莱米市，霍乱呈地方流行，季节性人口流动以及该湖这个潜在的环境储存库都可能促进疾病传播。卡莱米在2013 - 2016年开展了疫苗接种运动并改善了水、环境卫生和个人卫生状况。我们评估了这一干预措施的影响，以为地方流行环境中的未来防控策略提供参考。我们构建了考虑季节性人口流动和基于环境传播的 compartments 模型。我们估计了该干预措施避免的病例数，以及促进当地霍乱传播的各因素的相对贡献。我们估计在118周内该干预措施避免了5259例病例（95%可信区间：1576.6 - 11337.8）。传播并不依赖季节性人口流动，主要由环境驱动。消除环境暴露或污染可控制当地传播。反复的环境暴露可维持高人群免疫力，并降低疫苗接种在类似地方流行地区的影响。在这种环境中，应对环境暴露和污染应是干预措施的主要目标。
