Typical and atypical cutaneous leishmaniasis in Himachal Pradesh (India)

Visceral leishmaniasis (VL) is in elimination phase in India while cutaneous leishmaniasis (CL) is being reported from new foci. In Himachal Pradesh (HP), a foci of CL had been reported along Satluj River, but the causative agent poses a dilemma, hence the present study was undertaken in Shimla, Kullu and Kinnaur districts.

A total of 28 CL patients from Indira Gandhi Medical College and Hospital Shimla (IGMC) in 2018, were tested by rK39., Twelve fresh cases were subjected to microscopic detection of Leishmania parasite, PCR and sequencing. Skin biopsies of 3-4 mm diameter were cultured, as well as imprints were prepared for the detection of Leishmania amastigotes. Biopsy samples were inoculated into different culture media (M199, RPMI 1640, NNN) and were incubated at 22-24 °C. Polymerase chain reaction (PCR) was performed to characterize Leishmania parasite species.

Of 28 patients, one was positive by rK39 dipstick test and one imprint was found positive for Leishmania amstigotes. Twelve biopsy DNA samples subjected to PCR for Leishmania kDNA, were found Lesihmania positive. Identification of Leishmania species was confirmed by PCR-RFLP and sequencing method. Of 12 Leishmania positive samples, six were identified as L. donovani, three L. tropica, two L.major and one remained unidentified.

This study revealed the existence of three species of parasites i.e., L. donovani, L. tropica and L. major indicating the existence of typical and atypical leishmaniasis in Himachal Pradesh. The occurrence of CL cases in HP, Kerala or elsewhere should not be ignored considering them just cases of CL alone. Further studies are warranted to confirm the existence of L.donovani zymodeme MON37 from cases of CL in HP or L.donovani zymodeme MON2 strain causing VL in Bihar. Elimination of CL should also be considered along with goal of Kala -Azar elimination.