Comprehensive insights into leishmaniasis: From etiopathogenesis to a novel therapeutic approach

Leishmaniasis is a vector-borne disease caused by protozoan parasites of the genus Leishmania and is transmitted through the bites of infected sandflies. The disease is characterized by a variety of clinical manifestations, from small skin blemishes to large deformable ulcers, classified as cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL) and disseminated cutaneous leishmaniasis (DCL), as well as severe systemic infections (Kala-Azar or visceral leishmaniasis [VL]), affecting the spleen and liver, along with atypical forms such as lupoid leishmaniasis. As one of the world's most neglected tropical diseases, leishmaniasis threatens more than 1 billion people globally, with 12 million currently affected and <1.3 million new cases reported annually. This review provides comprehensive insights into the etiopathogenesis of leishmaniasis and explores the complex life cycle of parasites and their interactions with host immune responses. A systematic literature search was conducted across databases such as PubMed, Google Scholar, and Scopus via keywords such as "Leishmaniasis," "etiopathogenesis," "cutaneous leishmaniasis," "visceral leishmaniasis," and "Novel therapeutic approaches." Relevant studies published after 2015 were critically analyzed to present the current understanding of the disease mechanisms involved. It also highlights the current treatment landscape, emphasizing the emergence of drug resistance and the need for novel therapeutic approaches. Recent advancements in drug delivery systems, such as nanoparticle formulations, have shown promise for enhancing treatment efficacy and reducing toxicity. Additionally, integrated control measures, such as vector management and public education, are crucial for mitigating disease spread. This overview underscores the urgent need for continued research and innovation to combat this neglected tropical disease effectively.