Clinical study of cutaneous leishmaniasis in the Kashmir Valley

Sir, I read with interest the article by Wani et al. on the clinical study of cutaneous leishmaniasis (CL) in the Kashmir Valley.[1] The authors stated that the migration of people from villages to small townships coupled with climatic changes over the last few years could be the contributing factors for the emergence of a new focus of CL in the Kashmir Valley. However, they did not address exactly how climatic changes could influence the development of that new phenomenon. It is obvious that CL is a vector-borne human disease caused by Leishmania major, a unicellular eukaryotic parasite transmitted by pool blood-feeding sandflies mainly to wild rodents, such as Psammomys obesus. The people who share the rodent and sandfly habitats can be subverted as both sandfly blood resource.[2] Changes in climate could trigger the development of a new CL focus by the following mechanism. On one hand, the higher rainfall is expected to result in increased density of chenopods, a halophytic plant that constitutes the exclusive food of P. obesus. Consequently, following a high density of P. obesus, the pool of L. major transmissible from the rodents to blood-feeding female sandflies could lead to a higher probability of transmission to humans over the next season.[2] On the other hand, climatic changes could increase minimum temperatures sufficiently and create conditions suitable for endemicity that did not previously exist. Moreover, temperatures above a critical range suppress CL incidence by limiting the vector’s reproductive activity.[3] I presume that the emergence of new foci of CL in India over the recent years[1,4,5] necessitates conduction of epidemiological and molecular studies to determine the reservoir of infection, the vector, and the strains of causative leishmania.