Scientists at the Indian Institute 01Chemical Biology OICB), Calcuttare grappling wil , killer: Laishmania Donovani. It isprotozoa that derives its name fromits discoverers, Laishman anDonovani who discovered thepathogen at the turn of the centu !Isoon after Ronald Ross isolated themalaria parasite. Just as the malanparasite thrives Donovani finds its host in sand-fliinfesting the warn of eastern India. The sand-fly ijespecially rampant in Bihar where itbreeds in dark, damp cowsheds. A4a result, recurrent outbreaks of kalJazar have killed thousands in Sihasince the returndecades back.
A carrier flea releasesDonovanj into the human bloodstream every time it stings. And thipathogen swiftly navigates its wayto the liver and spleen, attackindthe organs' tissues. This causes anagging fever, depletion of whit4blood corpuscles, swelling of thebelly, and then death - if the dis4ease is not diagnosed in time.
The lIC8 has created a pathoger!bank with nearly 20 clinical isolatesof L Donovani preserved in cryo4genic (-700C) conditions, to be occasionally retrieved, implanted intolaboratory animals, and put back tohibernation. The protozoa'4enzyme profile has already beencharted and their DNA mappinqwould commence soon. Normally,blood tests do not reveal thqqpathogen, as its presence in theblood stream is negligible. Thi Imakes tissue culture from the liverand spleen - the nesting planes ofthe protozoa - necessary.