Characterisation of Leishmania Species Causing Cutaneous Leishmaniasis in Patients from Sokoto State, North West Nigeria Using Molecular Tools

Cutaneous leishmaniasis is an emerging neglected tropical disease in northwestern Nigeria, but Leishmania species identification relies predominantly on clinical observation in the absence of systematic molecular characterisation, limiting the understanding of local transmission ecology and treatment response. This study characterises Leishmania species causing cutaneous leishmaniasis in patients from Sokoto State, North West Nigeria using molecular tools. An analytical case series design was employed, recruiting 80 confirmed cutaneous leishmaniasis patients attending dermatology clinics at Usmanu Danfodiyo University Teaching Hospital and Sokoto Specialist Hospital. Skin biopsy and slit-skin smear samples were collected from active lesions and processed for Leishmania parasite isolation and DNA extraction. Species identification was performed by PCR amplification of the ITS1 region and heat shock protein 70 gene, followed by Sanger sequencing and phylogenetic analysis. Sandfly vector species were collected using CDC light traps in patient communities and identified morphologically. Evidence from 2020 to 2024 documents the co-circulation of Leishmania major and Leishmania tropica in West African arid-zone settings, with clinical presentations differing by species. This study generates the first molecular species characterisation dataset for cutaneous leishmaniasis in Sokoto State, filling a critical surveillance gap. Findings will be submitted to the Nigeria Centre for Disease Control, the WHO NTD Unit, and a dermatology-parasitology interface journal. Keywords: Leishmania species, cutaneous leishmaniasis, molecular characterisation, Sokoto State, ITS1.