Evidence of Visceral Leishmaniasis (Kala-azar) in Nepal 1996 - 1997

Abstract

Visceral leishmaniasis (Indian Kala-azar) first appeared in the Eastern Terai parts of Nepal during 1982. Dhanusha and Siraha districts were mostly affected. The present study reviewed epidemic situation with regards to Kala-azar in all 18 endemic districts of Terai for collection of morbidity and mortality statistics from different hospitals, health posts and health centres during 1996 and 1997. The kala-azar cases were tabulated age and sexwise. It has been found that children are more affected than adults, because the CFR in male child was 13% and 11% compared to female, 8% and 13%, during 1996 and 1997 respectively. Whereas CFR in male adults was 4% and in female only 3%. These cases were seen more from April to August. Kathmandu, the capital city of Nepal, which is non-endemic for Kala-azar, has shown signs of sand flies (Phlebotomus sps.). About 100-150 imported cases have been admitted and treated in Infectious Disease Hospital, Teku, Kathmandu during 1996 and 1997. They were infected in endemic districts of Terai before coming to Kathmandu. Sarlahi, Udayapur, Bara, Lahan and Siraha districts recorded 696 cases of Kala-azar with 11% CFR, 1160 cases with 7% CFR and 766 cases with 5% CFR during the year 1995, 1996 and 1997 respectively.

At present Aldehyde screening serology test is practised. A sensitive and specific serologic test for accurate diagnosis of leishmania should be made necessary and also for the detection of amastigotes in stained smears of aspirate from enlarged superficial lymph nodes, bone marrow or enlarged spleen. Leishmeniasis, both cutaneous and visceral, are endemic in the Terai districts. All these Terai districts are bordered with the northern districts of Bihar and West Bengal, India. Presumably, its simultaneous resurgence indicated long standing presence of visceral leishmaniasis (Kala-azar) in these areas and became source of infection to Nepal. It is a vector
borne parasitic disease and the vectors responsible are Phlebotomus species. Their population density increases in the month of July to September. At present no insecticide spraying is being practised for reducing vector population and controlling Kala-azar in Nepal. P. argentipes, fed on men, dogs, large animals and rodents, is an opportunistic feeder and shows both zoophilic and anthropophlic behaviour.