Spatial analysis of Leishmania donovani exposure in humans and domestic animals in a recent kala azar focus in Nepal.
Visceral leishmaniasis (VL) is a major public health problem in the Indian subcontinent where the Leishmania donovani transmission cycle is described as anthroponotic. However, the role of animals (in particular domestic animals) in the persistence and expansion of VL is still a matter of debate. We combined Direct Agglutination Test (DAT) results in humans and domestic animals with Geographic Information System technology (i.e. extraction maps and scan statistic) to evaluate the exposure to L. donovani on these 2 populations in a recent VL focus in Nepal. A Poisson regression model was used to assess the risk of infection in humans associated with, among other factors, the proportion of DAT-positive animals in the proximities of the household. The serological results showed that both humans and domestic animals were exposed to L. donovani. DAT-positive animals and humans were spatially clustered. The presence of serologically positive goats (IRR=9.71), past VL cases (IRR=2.62) and the proximity to a forest island dividing the study area (IRR=3.67) increased the risk of being DAT-positive in humans. Even if they are not a reservoir, domestic animals, and specially goats, may play a role in the distribution of L. donovani, in particular in this new VL focus.
Khanal
Basudha
B
BP Koirala Institute of Health Sciences, Dharan, Nepal.
Picado
Albert
A
Bhattarai
Narayan Raj
NR
Van Der Auwera
Gert
G
Das
Murari Lal
ML
Ostyn
Bart
B
Davies
Clive Richard
CR
Boelaert
Marleen
M
Dujardin
Jean-Claude
JC
Rijal
Suman
S
D000293:Adolescent; D000328:Adult; D000368:Aged; D000372:Agglutination Tests / Q000379:methods; D000818:Animals; D000829:Animals, Domestic / Q000469:parasitology*; D000913:Antibodies, Protozoan / Q000097:blood; D000953:Antigens, Protozoan / Q000276:immunology; D002020:Buffaloes / Q000469:parasitology; D002417:Cattle / Q000469:parasitology; D002418:Cattle Diseases / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D005260:Female; D040362:Geographic Information Systems; D015511:Goat Diseases / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission; D006041:Goats / Q000469:parasitology; D006801:Humans; D007893:Leishmania donovani / Q000276:immunology*; D007898:Leishmaniasis, Visceral / Q000453:epidemiology* / Q000469:parasitology / Q000635:transmission / Q000662:veterinary; D008297:Male; D008875:Middle Aged; D009390:Nepal / Q000453:epidemiology; D055815:Young Adult
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan