Leishmaniasis in the Middle East: A Narrative Review of Epidemiological Characteristics and Transmission Determinants

Leishmaniasis is a neglected tropical disease (NTD) caused by protozoan parasites of the genus Leishmania and transmitted through phlebotomine sandfly bites. The Middle East carries a disproportionate share of the global burden, shaped by armed conflict, ecological change, population displacement, and fragmented healthcare infrastructure. This narrative review synthesizes evidence from twenty-four peer-reviewed studies published between 2001 and 2026 on the epidemiological patterns, transmission determinants, and public health implications of leishmaniasis in the Middle East. Cutaneous leishmaniasis (CL) caused by Leishmania major and Leishmania tropica constitutes the dominant clinical burden, with Syria, Iraq, Iran, Lebanon, and Saudi Arabia reporting the highest case counts in the region. Visceral leishmaniasis (VL) caused by Leishmania infantum and Leishmania donovani contributes a smaller but significant burden in Iran, Iraq, and Yemen. Conflict-driven displacement, climatic variables, urbanization, poverty, and immunosuppression were identified as factors consistently associated with elevated transmission across the included studies, though the relative contribution of each factor could not be quantitatively established given the observational and surveillance-based nature of the available evidence. Most included studies relied on passive surveillance data, limiting the strength of conclusions that can be drawn. Significant gaps remain around HIV-VL co-infection, standardized cross-border surveillance, and treatment access in conflict-affected settings. Strengthening regional surveillance networks, expanding mobile diagnostic units, and integrating migrant health policies into national programs are among the public health responses identified across the included literature as warranting prioritization.