Epidemiology of a new focus of localized cutaneous leishmaniasis in Himachal Pradesh.

A new focus of localised cutaneous leishmaniasis has emerged along the Satluj River valley in the mountainous region of north west Himachal Pradesh. The main endemic region extends from Pooh subdivision of Kinnaur district to Kumarsain subdivision of Shimla district with adjoining Nirmand subdivision of Kullu District comprising 86 villages. The climate of the affected areas varies from temperate to subtropical. A total of 285 cases were recorded from 1988 to January, 2005. The age of these patients varied from 10 months to 75 years, with 63 children (<12Years), and a male to female ratio of 1: 0.9. The duration of disease was 15 days to 48 months with majority (85%) presenting between 1-6 months. The number of lesions varied from 1-8, and were mostly seen on exposed parts of the body. Morphologically, lesions were asymptomatic, dry, nodular or crusted nodulo-ulcerative plaques. Tissue smear positivity for amastigotes was 43%. The characterization of 14 strains of these Leishmania revealed presence of both Leishmania tropica (n=3) and Leishmania donovani (n=11). Identification of the 42 sandflies collected from the peridomestic environment of the patients, revealed Phlebotomus longiductus - 29, P. major 8, P. kandelaki 2, while 2 remained unidentified. The patients were treated with intralesional sodium stibogluconate and majority showed excellent response.