Assessing water-related risk factors for Buruli ulcer: a case-control study in Ghana.

To assess water-related risk factors of Buruli ulcer, a case-control study of 102 patients (51 cases and 51 controls) was undertaken by matching age group, sex, and bacille Calmette-Guerin (BCG) vaccination history in Ghana. The factors used here for matching have previously been implicated as factors of Buruli ulcer, an emerging infectious disease. This is the first study to delineate a set of previously suspected, water-related risk factors, in a case-control study matching for age group, sex, and BCG vaccination status. The results of both bivariate and multivariate analyses presented a significantly high odds ratio (OR) only for swimming in rivers on a habitual basis (OR = 18.00, P < 0.01) among the major water-related risk factors. Use of water from rivers and ponds for drinking, cooking, bathing, and washing purposes were not significant risk factors. Our data suggest that swimming, or activities on riverbanks associated with it, is a risk factor.