Biological, Environmental, and Social Determinants of Buruli Ulcer in Africa: Their Interplay Across Disease Severity and Patient Outcome.

Buruli ulcer (BU), caused by Mycobacterium ulcerans, is a neglected tropical disease influenced by interacting biological, environmental, and social determinants in Africa. Biological factors include mycolactone-mediated immunosuppression, host immune response, lesion severity, age, HIV infection, genetic susceptibility, and delayed diagnosis. BU primarily affects children under 15 years, whereas HIV co-infection may contribute to more severe outcomes. Early rifampicin-based antibiotic therapy improves healing and reduces complications, whereas delayed treatment is associated with larger lesions, increased need for surgery, and long-term disability. Environmental factors, including aquatic exposure, rainfall, flooding, land-use changes, and ecological disturbances, may influence the distribution and exposure patterns of M. ulcerans. However, specific pathways of human transmission remain uncertain. Social determinants such as poverty, stigma, low education, gender roles, spiritual beliefs, reliance on traditional healers, and limited healthcare access contribute to delayed care-seeking. In Ghana, the median time to treatment was 25 days for pre-ulcer lesions and 204 days for ulcerative disease. BU occurs in at least 32 countries, with prevalence ranging from 3.2 to 26.9 per 10,000 population in endemic areas. Integrated strategies combining early detection, antibiotic therapy, wound care, physiotherapy, psychosocial support, stigma reduction, and community engagement are essential.