Lymphatic filariasis in two distinct communities of upper Assam

Current status of bancroftian filariasis among two distinct communities of Upper Assam was evaluated. High prevalence (10.3% mf rate) in tea workers descendents of tribals migrated from endemic states such as Orissa, Bengal, Uttar Pradesh and southern states of India, were recorded. Among non tea workers (indigenous population) significantly low mf rate was found in spite of the fact that both the communities are living in close vicinity and in similar ecological and mosquitogenic conditions. Culex quinquefasciatus was incriminated as vector in the areas of both the communities. A group of recent migrants of Bihar and Bengal living in the locality of non tea worker population were also found microfilaraemic. Significantly lower infection rate in non tea worker population appears to be associated with host susceptibility to the infection. Familial clustering in microfilaraemic subjects noticed in tea workers group also suggests involvement of racial susceptibility to infection.