Clinical case estimates of lymphatic filariasis in an endemic district of Bangladesh after a decade of mass drug administration.

BACKGROUND Bangladesh has a high burden of lymphatic filariasis (LF) disease. This survey estimated the current number of clinical cases in a historically endemic district after a decade of mass drug administration (MDA). METHODS A cluster survey was conducted in 30 villages of Nilphamari District. Ten households per village were randomly selected, and individuals with LF clinical conditions identified. Hydrocoele and lymphoedema (leg, arm, breast) cases were quantified and mapped, and differences by sex, age, severity of disease and episodes of acute dermatolymphangioadenitis attacks (ADLA) examined. RESULTS From 1242 surveyed >10 years old 55 individuals (4.4%) with LF clinical conditions were identified. Males were mostly affected by hydrocoeles, and females by leg lymphoedema. Higher prevalence and more advanced stages of disease were found in older age groups. CONCLUSIONS Overall low prevalence of severe clinical disease was found, which has positive implications for the elimination goal. Future planning of MMDP strategies will need to address the varying clinical conditions, severity of disease and impact of ADLAs affecting different sub-groups of the population. It will also be important to monitor for new cases, and examine the shift in age distribution of cases over time