Leishmaniasis: Global Epidemiology, Transmission Dynamics, and Integrated Control Strategies

Abstract

Leishmaniasis is a globally significant vector-borne zoonotic disease caused by protozoan parasites of the genus Leishmania, affecting humans and various mammalian hosts, transmitted through the bite of infected sand flies. It manifests primarily in three clinical forms: visceral, cutaneous, and mucocutaneous leishmaniasis, each varying in severity and geographic prevalence. This disease is endemic in tropical and subtropical regions, with over one billion people at risk, especially among marginalised populations in developing countries. Transmission occurs via infected female phlebotomine sand flies, with both zoonotic and anthroponotic cycles contributing to disease persistence. Domestic dogs are primary reservoirs, though rodents and cats contribute, particularly in zoonotic transmission cycles. Despite ongoing control efforts, drug resistance, vector adaptability, and resource limitations continue to pose major challenges as the global burden remains substantial, with estimated annual cases ranging from 600,000 to 1 million for CL and 50,000 to 90,000 for VL, accompanied by significant morbidity and mortality. Environmental changes, urbanisation, and human mobility are expanding leishmaniasis into previously non-endemic areas. Comprehensive control strategies require integrated approaches encompassing vector control, reservoir management, early diagnosis, treatment, and surveillance to mitigate this neglected tropical disease’s impact worldwide.