Indian Schistosomiasis - An Introduction

The first case of schistosomiasis was reported from a boy by Hatch in 1878 from India. Since then many cases of human schistosomiasis were reported from different parts of the country but raising controversies mainly because of absence of related snail species. Not withstanding this fact, an endemic focus of human schistosomiasis was identified in Gimvi village of Ratnagiri district where a new snail species ( Ferrissia tenuis) was claimed as its new intermediate host. This raised many questions , most of them remained unanswered. Further , eggs of a native blood –fluke species (Schistosoma incognitum) were detected in two human stools suggesting it as new human schistosomes species. When its adults were recovered frm pigs, the original finding came under controversy. Thus India or for that matter whole South Asia is a fascinating place which has many answers for the global problem of schistosomiasis. Nevertheless, Indian scientists are working on schistosomiasis in isolation since international organizations have completely neglected the whole geographical area.

Jabalpur, within Madhya Pradesh, India, is the place where fossils of Dinouser’s eggs have been recovered. This is the place where atleast six mammalian schistosome species ( Schistosoma spindale,S.indicum, S.nasale, S.incognitum,Orientobilharzia dattai, Bivitellobilharzia nairi) do occur in animals.India is the place from where six schistosome species ( S.indicum,S.incognitum,S.spindale,S.nasale,O.dattai, B.nairi ) have originated.

There are many questions to be solved by the scientific community. What is the interplay between these species in intermediate and final hosts? Why Indian schistosomes are poor egg producers? What are the chances of cross-fertilization and formation of new hybrids ?Why Indian schistosomes are responding differently to well known schistosomicides ? Is there any co-relation between infertility or low milk production in bovines to latent schistosome infections ? How many schistosomes species have remained unidentified ? Why Indian schistosomes have not evolved through river routes ? How the fluke behaves in immunologically compromised man ? What is the fate of schistosome species in human cases of cercarial dermatitis ?

We consider African schistosomes as the predecessors of all the schistosomes including those of India . But Indian schistosomes are apparently well tolerated or well adapted to their final hosts causing comparatively less injury. Who has, then, originated first ?

I ,as Indian Veterinary Parasitologist has devoted my whole academic life to understand schistosomes and schistosomiasis in India. In my latest work as Emeritus Scientist,ICAR , we conclusively proved efficacy of triclabendazole in treating schistosomiasis including nasal schistosomiasis.I am still interested to spread knowledge on schistosomiasis to other countries and willing to participate in any such program. Any interested institute/organization/scientist may contact me.