[Bancroftian filariasis in Madagascar: persistent endemicity].

A major study was conducted to determine the prevalence of Bancroftian filariasis in 9 health districts located mainly on the east and north coast of Madagascar between 1995 and 1997. The study population included 2524 people 10 years or older. On the east and north coast, the incidence of microfilarial carriers varied depending on location from 7 p. 100 to 47 p. 100 in men and 3 p. 100 to 33 p. 100 in women. The highest incidences, i.e., around 33 p. 100 in both sexes, were observed in the southeastern districts of Ifanadiana, Manakara, and Vangaindrano. In the other districts on the east coast, the highest rates occurred mainly in men, i.e., 47 p. 100 in Vavatenina, 33 p. 100 in East Feneriva, and 33 p. 100 in Mahanoro. Only two districts on the west coast were studied, i.e., Marovoay where the incidence was zero and Ankazoabo where the prevalence was 4 p. 100 for men and 3 p. 100 for women. The results are compared with those of a study carried out in 1958. At 16.22 p. 100, chronic morbidity is relatively common in men but less disabling, i.e. mainly scrotal and member elephantiasis and hydroceles. Chronic morbidity was only 2.26 p. 100 in women, i.e. mainly member elephantiasis. Control of Bancroftian filariasis may be achievable by targeted use of drug prophylaxis and bednets in zones of high prevalence.