Fasciolopsis Buski in Saharsa District (North Bihar)

The infection of intestinal flukes is endemic in a big area of Saharsa District and is a great public health problem. It has affected mostly the poor people and has devitalised such a population leading to a great economic loss. In order to study the life cycle and source of infection of F. buski about two thousands snails from different tanks and pools of the affected areas were studied. Out of the snails studied about 75 per cent were of species vivipara, 21 per cent lymnosa and 4 per cent planorbis. These snails were dissected and examined for cercarise. Leptocercii were observed in three of the planorbis snails. These Leptocercii had considerably simple and narrower tails than their bodies and had no birstles on their tails. They were taken as cercarise of F. buski. In some of the snails cercarise with bifid tails were observed. They were neglected as they were considered, to be cercarise of animal flukes. The cercarise of F. buski do not require second intermidiate host. They encyst on various water plants and tubers which are found in the ponds and pools of the endemic area. Attempts were made to study these tubers when brought fresh from such ponds. Only in one case two encysted cercarise were observed. These tubers and nuts will be studied in detail after the monsoon is over. The snails are found in abundance in these warm and stagnant pools (chaurs) and ponds. The different types of tubers such as saruk, karhar and ghechuls abound in these pools. Besides above, bhent and singhara are also grown in some of these tanks. Those tubers and nuts are infected with the cercariae. These tubers are eaten very frequently by the poor people of these affected areas on account of usual scarcity of food in certain months of the year. No doubt, these tubers are usually taken after they are boiled and their skin is peeled off. In several cases these tubers and nuts are peeled with teeth when raw, specially during collecting them from water. In this way the encysted embryos gain access to the mouth and infection taken place. It is not uncommon to observe that even some of the high caste people have got this infection as they ingest the encysted cercariae while removing the outer covering of the edible aquatic fruits or tubers with teeth when raw at the time of working in the neighbouring fields of such pools or tanks. Most common age incidence is below 25 years. It has been found in both sexes but men are more commonly affected. In most of the cases the poor persons are usually the victims. August, September and October are the common months in which these tubers are taken out and eaten.