Bancroftian filariasis in Namrup tea estate, district Dibrugarh, Assam.

Filariasis survey in a randomly selected tea estate of district Dibrugrah revealed 6.7% infection of Wuchereria bancrofti in labour population with microfilaria (mf) rate of 7.6% in males and 5.9% in females. The mf rate increased progressively with the age which however, dropped in 31-40 age group of males and in 41-50 age group of females. Chronic filariasis diseases rate was 2.7%. The involvement of genitals in manifesting chronic filariasis was significantly higher than of the lower extremities. Infection and infectivity rates in the vector mosquito, Culex quinquefasciatus were 6.1% and 4.6% respectively with mean L3 load per infective mosquito of 8.5. Drains, land, peridomestic ditches were chief breeding habitats of Cules quinquefasciatus in the tea estate.