Schistosoma Indicum

Schistosoma indicum is a species of digenetic trematode in the family Schistosomatidae.

The parasite is widespread in India and other Asian countries.

The most important the first intermediate host is a freshwater snail Indoplanorbis exustus that is the sole natural intermediate host for Schistosoma indicum (and other two Schistosoma species) on the Indian sub-continent. Earlier another snail (Lymnaea luteola) was also implicated in transmission of Schistosoma indicum but subsequent research by Srivastava and Dutt (1962) refuted any such possibility.

Schistosoma indicum was discovered by the British scientist R. E. Montgomery, in 1906, from a horse from Mukteswar, Uttar Pradesh, India. This blood-fluke causes hepato-intestinal schistosomiasis in many domestic animals (sheep, goat, water buffalo, cattle, camel, horse, donkey, dog, but not pigs). It was responsible for an outbreak of pulmonary schistosomiasis, in 1981, in sheep in Rajasthan, leading considerable mortality. S.indicum caused considerable mortality in the sheep flocks in Andhra Pradesh and Karnataka but it was misdiagnosed as Rinder Pest ( Chandra et al 2003) highlighting the problem of proper diagnosis of the infection in domestic animals. S.indicum has been detected from almost all the states of India and in that respect, it is more wide spread than Schistosoma spindale (Agrawal,2012).

A variant of Schistosoma indicum, rather than Schistosoma haematobium, was suggested (Gaitonde et al 1981) to be responsible for human schistosomiasis in Gimvi village, Ratnagiri district, India but was later disputed by other scientists. The main reasons were the use of a different intermediate host (Ferrissia tenuis) and final host (man) with difference in location (urinary system ) which is not possible for any variant (Agrawqal,2012). Terminal-spined Schistosoma indicum-like eggs have been detected in human stools, too. Dr M. C. Agrawal demonstrated cross-immunity against Schistosoma incognitum by immunising the host against Schistosoma indicum.