Prevalence of bancroftian filariasis and associated factors in the urban district of Lindi, Tanzania.

In September 1995, a cross sectional study was done in Lindi urban. The aim was to determine the magnitude of filarial infection and the population perceptions on its causes, transmission, prevention and treatment. A total of 872 people aged 10 years and above from four wards were interviewed. Clinical examination to detect hydrocele and elephantiasis was carried out. Also, nocturnal blood samples were collected and examined to detect microfilaraemia. The results show that hydrocele and elephantiasis were recognized as health problems in the community (79.2% and 77.8% respectively). However, only 26.6% and 42.2% of respondents, respectively knew that the conditions were mosquito transmitted. Various beliefs of causation for hydrocele and elephantiasis were reported. However, higher proportions of respondents believed in the "will of God" ( 31% and 36.4% respectively). Whereas, 85.9% of the respondents knew that hydrocele can be surgically treated, 57.1% believed that hydrocele cannot be prevented and 51.3% believed so for elephantiasis. A total of 76.2% of the respondents were using anti-mosquito measures; the mosquito-net was the most popular, used by 60% of the respondents. People using nets had statistically significant lower microfilaria prevalence than non users. The prevalence of microfilaraemia was 12.1% (95% CI 9.6% - 14.6%). The prevalences of the chronic sequelae were 13.5% (95% CI 9.9% - 17.1%) for hydrocele, 5.2% (95% CI 3.7% - 6.7%) for limb elephantiasis and 0,5% (95% CI 0% - 1.3%) for scrotal elephantiasis. The current prevalence of microfilaraemia and hydrocele suggests that transmission continues unabated in the community due to general lack of knowledge on causes, transmission, prevention and organized control programme for Bancroftian filariasis. It is recommended that an intervention programme for prevention be developed for the area.