Cutaneous and Visceral Leishmaniasis Caused by the Same Zymodeme of Leishmania donovani in Kerala, India

Abstract

The tribal population in and around the Western Ghats region of India is affected by both cutaneous leishmaniasis (CL) and visceral leishmaniasis (VL) with typical clinical symptoms. In this study, we recorded and analyzed seven CL and three VL cases from this emerging belt. All the cases were found as autochthonous transmission. Multiple genetic markers (minicircle kinetoplast DNA polymerase chain reaction and restriction fragment length polymorphism of 3'untranslated region heat shock protein (HSP) 70, a larger segment of HSP 70, and 6-phosphogluconate dehydrogenase [PGDH] gene sequences) were used to identify and characterize the parasite. It was found that both clinical manifestations are caused by zymodeme MON-37 of Leishmania donovani. We have investigated the detailed entomological and epidemiological aspects of disease transmission. An abundant population of the proven vector Phlebotomus argentipes was observed in the study villages.

Figure 1.

Data showing the distribution and diagnosis of cutaneous and visceral leishmaniasis cases in the Western Ghats region of Kerala. (A) The map represents the distribution of visceral leishmaniasis/cutaneous leishmaniasis (VL/CL) cases in the foothills of Western Ghats, Kerala, India. (B–D) A nodular patch on the right leg of a CL patient (B) and Leishmania amastigotes in skin aspirate (C) and skin biopsy (D) samples were analyzed by histopathological examination. (E–G) The patient was diagnosed as having VL (E) and the Leishmania amastigotes in the histopathology of the liver (F) and bone marrow (G). Red arrowheads indicate the Leishmania amastigotes forms.

Figure 2.

(A) Polymerase chain reaction‒RFLP pattern of 3′UTR of the HSP 70 gene using Hae III. (The lowest band of 25 bp is very faint in the agarose gel). (B) Single nucleotide polymorphism showing the nucleotide change (A→G) at the 976th position of the 6-PGDH gene. (C) Phylogenetic analysis of the HSP 70 gene. (D) Phylogenetic analysis of 6-PGDH gene sequences from dermatropic and viscerotropic clinical manifestations of Leishmania donovani. RFLP = restriction fragment length polymorphism; UTR = untranslated region.