Leishmaniasis

Abstract

Leishmaniasis is an endemic disease in Asia, Africa, the Americas and Southern Europe caused by Leishmania parasites and transmitted through the bite of female sandflies, resulting in Leishmania replication in macrophages. The condition manifests either as visceral leishmaniasis, a potentially fatal systemic disease that causes persistent fever, enlargement of the liver and spleen (hepatosplenomegaly), and a reduction in almost all blood cells (pancytopenia), or as cutaneous leishmaniasis, characterized by ulcerative or non-ulcerative skin lesions. Disease manifestation and severity are determined by parasite, host and vector characteristics, with a complex immunological interplay. The rK39 rapid diagnostic test is the primary diagnostic method for visceral leishmaniasis, while cutaneous leishmaniasis is commonly diagnosed by microscopy of skin samples. Visceral leishmaniasis and severe forms of cutaneous leishmaniasis are managed by systemic treatment. For localized cutaneous leishmaniasis, treatment involves topical therapies, including cryotherapy, thermotherapy and/or intralesional injections with antimonials. The WHO 2021-2030 roadmap of neglected tropical diseases aims to eliminate visceral leishmaniasis as a public health problem and to achieve enhanced control of cutaneous leishmaniasis. In South Asia, a regional visceral leishmaniasis programme has dramatically reduced the caseload. Eastern Africa has recently launched a similar initiative. Sustainable progress in the control and elimination of leishmaniasis will require better diagnostics, treatment and vector control interventions as well as progress in vaccine development, political commitment, improved surveillance and healthcare services.