A lymphatic filarial survey revealing a focus of Brugia malayi in the coastal region of west Bengal.

Random night blood samples were examined from 528 subjects in an endemic zone of lymphatic filariasis, in the coastal region of West Bengal. There were 136 cases out of 528 who were symptomatic, with or without recurrent episodes of fever, lymphangitis and lymphadenitis and with various degrees of lymphoedema. Examination of blood samples revealed microfilaria in 43 cases of which 42 were asymptomatic and only one was symptomatic with lymphoedema. All the microfilariae were of the species Brugia malayi.

Studies on the life cycle of Artyfechinostomum oraoni Bandyopadhyay, Manna & Nandy 1989: embryogenesis & development in the intermediate host.

A study was undertaken to elucidate the life cycle of the parasite A.oraoni, isolated from man. For the purpose, operculated eggs were isolated from faeces of oraon tribals belonging to the village Bandipore, district North 24-Parganas of West Bengal province of India. The purified eggs were incubated at different temperatures, salinity and pH. Larvae (miracidia) could be observed to develop between the 7th and 8th day of incubation at a temperature range between 22 degrees-30 degrees C. While the optimum pH was observed to be neutral, larval development did not take place at salinity beyond 0.8 per cent. To identify the correct intermediate host, all available species of snails from the study village were colonised and infected with the laboratory hatched miracidia from human derived operculated eggs. It was observed that of all the snails infected, only Lymnaea supported the development of rediae from miracidia, which could be observed on the 32nd post infection day. Considering the results of the experimental study, it was hypothesised that Lymnaea spp. of snails under natural condition also, might act as the first intermediate host for A. oraoni.