Cholera in Sub-Saharan Africa: From the Biology of Vibrio Cholerae to the Challenges of Surveillance, with a Focus on the Democratic Republic of the Congo

Cholera remains a major public health problem in sub-Saharan Africa, where limited water and sanitation, population displacement, conflict and weak health systems sustain recurrent epidemics. Interpreting its epidemiology requires linking the biology of Vibrio cholerae, antimicrobial resistance, and the performance of surveillance and diagnosis. We conducted a structured narrative review, prioritising meta-analyses, systematic reviews, epidemiological and genomic studies, and WHO and Global Task Force on Cholera Control (GTFCC) documents, with emphasis on sub-Saharan Africa, the Great Lakes region and the Democratic Republic of the Congo (DRC). Cholera in the region is a system combining an aquatic reservoir, foci of person-to-person transmission, structural determinants (water, sanitation and hygiene, rainfall, conflict, displacement) and repeated introductions of seventh-pandemic lineages. In the eastern DRC, genomic data show stable AFR10 sublineages persisting around the Great Lakes, with a ciprofloxacin-reducing parC mutation in one Lake Tanganyika clade. Resistance to historical antibiotics is common but heterogeneous across countries, years and laboratory methods, and data from central Africa are sparse, notably for macrolides. Laboratory surveillance is essential but limited by testing coverage, specimen transport and variable case definitions, which bias confirmed-case counts and positivity rates. Single-dose oral vaccination, water, sanitation and hygiene, and targeted response around cases are complementary, and none is sufficient alone. Understanding and controlling cholera in the DRC requires locally documented, standardised laboratory data reported with explicit denominators, stronger decentralised confirmation and genomic surveillance, and sustained investment in prevention. We identify four research priorities to guide integrated surveillance and outbreak response.