The sandflies of the Satluj river valley, Himachal Pradesh (India): some possible vectors of the parasite causing human cutaneous and visceral leishmaniases in this endemic focus.

BACKGROUND & OBJECTIVES: The recently recognized endemic focus of leishmaniasis in Satluj river valley in Himachal Pradesh (India) lies in north-western Himalayas (30 degrees N, 70 degrees E). This endemic focus of leishmaniasis appears peculiar where localized cutaneous leishmaniasis (LCL) co-exists with visceral leishmaniasis (VL), and Leishmania donovani is predominant pathogen for LCL whereas only a few cases have been due to Leishmania tropica. This study was carried out to collect sandflies, identify and delineate their habitat and role in transmission of human leishmaniasis in this endemic focus. METHODS: During June 2003 to September 2007, 142 (M-22, F-120) sandflies were collected with aspirators from 10 endemic villages of Kinnaur and Shimla districts. RESULTS & CONCLUSION: Sixty-two of the identified sandflies caught belonged to the genus Phlebotomus species, including some species that are known to act as vectors of the parasites causing human leishmaniasis. The Phlebotomus (Adlerius) chinensis longiductus (Parrot), 1928 (28 sandflies), P. major (8 sandflies), P. (Larroussius) kandelakii burneyi (Lewis), 1967 (8 sandflies) were identified. The identification of the main species of vector sandfly in the region is complicated because it is still uncertain which Leishmania species cause(s) the local human leishmaniasis. Circumstantially it seems likely, however, that Phlebotomus (Adlerius) chinensis longiductus is the main vector. Other species found, such as P. major and P. (Larroussius) kandelakii burneyi, may also be responsible for some cases. A more elaborate study is recommended.