Epidemiology of bancroftian filariasis in a semi-urban community of Kerala State.

A community-based longitudinal study was initiated in 1983 in a semi-urban area, endemic for bancroftian filariasis to determine the incidence and prevalence, natural history and clinical pattern of filarial infection and also to study the impact of control measures on it. The base-line filariometric indices observed during the initial clinico-parasitological survey and entomological observations made during the first 12 months of this study are highlighted in this paper. 5.5 per cent of the examined population had microfilaraemia with average infestation of 8.1 per 20 cmm. The microfilaraemia found to have significant (P less than 0.001) relationship with age, but not with sex (P greater than 0.05). The filarial disease which had the prevalence of 3.6 per cent showed a significant (P less than 0.001) relationship to both age and sex. The youngest microfilaria (mf) carrier was of 2 years and with filarial swelling was of 6 years age. A significant (P less than 0.001) relationship of educational status and family size was observed with disease while it was non-significant (P greater than 0.05) with microfilaraemia. With the increase in per capita income of the individuals, a significant decrease in number of persons with microfilaraemia (P less than 0.01) as well as with disease (P less than 0.05) was noted. Culex quinquifasciatus, the vector for this infection was prevalent throughout the period of observation with highest density in September. Vector infection and infectivity rates ranged from 0 to 4.4 per cent and 0 to 2.2 per cent respectively.

Epidemiology of brugian filariasis in a rural community of Kerala State.

The baseline clinico-parasitological parameters collected during the initial survey and the entomological observations made during the first year as a part of a longitudinal study undertaken in a brugian endemic rural community are presented in this paper. Out of the total (11.604) examined population, 8.1 per cent had microfilaraemia and 7.6 per cent had filarial disease. A highly significant (P less than 0.001) relationship of age was observed with microfilaraemia and the disease. The filarial disease rate showed no significant difference between two sexes while the microfilaria (Mf) rate was significantly (P less than 0.001) higher in males than females. A significant (P less than 0.001) relationship of microfilaraemia as well as of filarial disease was found with the income and the educational status of the individual. The mf and the disease rates did not differ by the family size except those families with 1-3 members. However, the relationship of family size was found to be significant (P less than 0.001) with disease and non-significant (P greater than 0.05) with microfilaraemia. The vectors were prevalent throughout the year but the infection was mostly confined to Mansonia annulifera.