RAISING EXPERIMENTAL INFECTION OF PARAMPHISTOMOSIS IN SHEEP UNDER LABORATORY CONDITION

Abstract

Snails, the intermediate host are the transmitter of trematode infection in ruminants in the endemic areas of Punjab. Under DST-SERC-FAST-Track project(DST, GOI, New Delhi), the survey was conducted mainly in ponds, bank of the River Satluj and Beas its surrounding temporary water bodies, ditches, impoundments, near by tube well sand paddy fields in Ludhiana, Hoshiarpur Kapurthala and Amritsar district of Punjab. A total of 701 snails were collected, and seven species were identified as Indoplanorbis exustus, Gyraulus convexiusculus, Lymnaealuteola, L. auricularia, Bellamya (Vivipara) bengalensis, Corbicula striatella, and Thiara tuberculata. Out of the total collected snails, 365, 4, 165, 127, 16 and 24 were contributed by I. exustus, G. convexiusculus, Lymnaeasp., B. bengalensis, C. striatella and T. tuberculata respectively. Snails like I. exustus, G. convexiusculus and Lymnaeasp were found to be most prominent in ditches, impoundments, nearby tube wells and paddy fields which play a very important role in the transmission of most pathogenic diseases like paramphistomosis and schistosomosis in ruminants respectively. The other snails were recorded to be common in bank of the River Satluj and its surrounding temporary water bodies. I. exustusan intermediate host of Paramphistomum spp. were kept in different batches individually in glass tubes as per Leiper's glass tube technique. Snails in bulk were also kept in beaker, surgical tray, earthenpots and petridishes with coloured poly then estrips to harvest metacercariae. Polythene strips of different colour, green, yellow and pink were used for the encystment of cercariae. These strips were stuck to the inner surface of the petridishes, beakers and surgical tray. Various encystment materials like water plants; lettuce and itsit (Trienthemagovinda) leaves were used. It was observed that maximum attraction of cercariae was towards itsit leaves followed by green and yellow polythene strips. Very few cercariae were also encysted onthe wall of the containers. 185 individuals of I. exustuswere found to be shedding cercariae with the prevalence rate of 55.89%. The cercariae were identified ascerearia of Paramphistomum epiclitum. The collected metacercariae were used for raising the infection in sheep. A total of 12,040 metacercariae was collected from185 infected snails (I. exustus) and kept in polyvinyl tubes (stored at 4°C). These metacercariae were given orally to two sheep for raising paramphistome infection under experimental condition. The animals were subjected with 4000 metacercariae to each sheep. The grass with encysted metacercariae was also collected from thefields for feeding to sheep. Faecal samples examined microscopically and found positive for paramphistome eggs after 135 days post infection. The experiments confirm the transmission of paramphistome infection in sheep. This disease is highly pathogenic and there is a need to formulate control and preventive measures for the betterment of livestock industry