Lymphatic filariasis morbidity mapping: a comprehensive examination of lymphoedema burden in Chikwawa district, Malawi

Background: Managing lymphatic filariasis (LF) morbidity and reducing disability is one of the two primary goals of the Global Programme to Eliminate Lymphatic Filariasis. However, in order to achieve this, the geographical distribution of LF morbidity needs to be better estimated. Methods: All cases of lymphoedema within a single health centre catchment area (pop. 42 000) in the southern region of Malawi were examined. Maps of lymphoedema burden were produced and trends in patient demographics, severity of lymphoedema (Dreyer staging) and health-seeking behaviour were explored. The number of lymphoedema cases was compared with records maintained by the Ministry of Health, Malawi. Results: A total of 69 lymphoedema cases were identified (32 per 10 000 population), of which 48 (70%) were female and 21 (30%) male. The majority of cases (51/69) had Dreyer stage 2-3, and almost all (65/69) had experienced acute attacks as a result of their lymphoedema. This burden was much greater than that estimated by Ministry of Health (33 cases). Conclusions: Current case detection methods underestimate the burden of lymphoedema in Malawi. There is a continued need to develop new LF morbidity identification and surveillance approaches to ensure that future morbidity management strategies are effectively targeted.