Prioritizing interventions for cholera control in Kenya, 2015–2020.

Kenya has experienced cholera outbreaks since 1971, with the most recent wave beginning in late 2014. Between 2015–2020, 32 of 47 counties reported 30,431 suspected cholera cases. The Global Task Force for Cholera Control (GTFCC) developed a Global Roadmap for Ending Cholera by 2030, which emphasizes the need to target multi-sectoral interventions in priority cholera burden hotspots. This study utilizes the GTFCC's hotspot method to identify hotspots in Kenya at the county and sub-county administrative levels from 2015 through 2020. 32 of 47 (68.1%) counties reported cholera cases during this time while only 149 of 301 (49.5%) sub-counties reported cholera cases. The analysis identifies hotspots based on the mean annual incidence (MAI) over the past five-year period and cholera's persistence in the area. Applying a MAI threshold of 90th percentile and the median persistence at both the county and sub-county levels, we identified 13 high risk sub-counties from 8 counties, including the 3 high risk counties of Garissa, Tana River and Wajir. This demonstrates that several sub-counties are high level hotspots while their counties are not. In addition, when cases reported by county versus sub-county hotspot risk are compared, 1.4 million people overlapped in the areas identified as both high-risk county and high-risk sub-county. However, assuming that finer scale data is more accurate, 1.6 million high risk sub-county people would have been misclassified as medium risk with a county-level analysis. Furthermore, an additional 1.6 million people would have been classified as living in high-risk in a county-level analysis when at the sub-county level, they were medium, low or no-risk sub-counties. This results in 3.2 million people being misclassified when county level analysis is utilized rather than a more-focused sub-county level analysis. This analysis highlights the need for more localized risk analyses to target cholera intervention and prevention efforts towards the populations most vulnerable. Author summary: Kenya has experienced recurrent cholera outbreaks from 1971 through today and constraints on resources make it essential to target multi-sectoral interventions to high priority areas. Using surveillance data from 2015–2020, this study identifies high priority areas for cholera intervention in Kenya following guidance from the Global Task Force on Cholera Control. We identified that roughly 3 million people (6% of the population) in 13 sub-counties live in high priority areas in Kenya, where the mean annual incidence exceeded 70 cases per 100,000 population and over 35% of weeks reported at least one suspected cholera case. Further, 1.6 million people living in high priority sub-counties would have been de-prioritized had the analysis been performed only at the county scale. Cholera interventions in Kenya should target high priority sub-counties, and future countries undergoing cholera control planning should carefully consider operational implementation when determining the spatial scale of their prioritization analysis. [ABSTRACT FROM AUTHOR]