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.

valley in Himachal Pradesh (India) lies in north-western Himalayas (30°N, 70°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.

The rK39 immunochromatic dipstick testing: a study for K39 seroprevalence in dogs and human leishmaniasis patients for possible animal reservoir of cutaneous and visceral leishmaniasis in endemic focus of Satluj river valley of Himachal Pradesh (India).

BACKGROUND: The newly recognized endemic focus of leishmaniasis in Satluj river valley of Himachal Pradesh (India) has both localized cutaneous leishmaniasis (LCL) and visceral leishmaniasis (VL) predominantly caused by Leishmania donovani. Rapid rK39 immunochromatographic dipstick test detects circulating antibodies to recombinant K39 antigen of L. donovani-infantum complex and is highly specific/sensitive in diagnosing symptomatic or asymptomatic infection in humans and dogs. METHODS: The sera from two VL patients and 13 LCL patients, and 31 dogs were subjected to rK39 immunochromatographic dipstick testing with an aim to identify possible animal reservoir for leishmaniasis in this endemic focus. RESULTS AND CONCLUSION: The positive rapid rK39 immunochromatographic dipstick test in 100% VL and 31.8% LCL patients, and 6.5% dogs suggests that both VL and LCL in this focus are apparently being caused by L. donovani-infantum and that reservoir infection is perhaps being chiefly maintained in asymptomatic dogs. However, it needs corroborative evidence in the form of in-vitro parasite cultivation and/or PCR studies for confirmation. A more elaborate study is recommended.