Abstract
OBJECTIVES: This study investigated emergence of visceral leishmaniasis (VL) in 2021, in Kajiado County in Kenya, representing a newly recognized region of endemic transmission. METHODS: The investigation involved community sensitization, medical camps, and entomological surveys across eight villages. We screened 100 individuals with indicative symptoms of leishmaniasis, and also carried out an entomological survey. RESULTS: We found 10 patients of VL, predominantly in children under 15. Of 22 suspected cutaneous leishmaniasis (CL) cases, eight were confirmed with Leishmania tropica. Entomological surveys identified 4781 sandflies, with Sergentomyia species being most abundant. DNA of Leishmania donovani was detected in multiple Sergentomyia species and Phlebotomus saevus, while L. tropica DNA was found in P. saevus. Blood meal analysis revealed a strong preference for human blood, followed by goats, indicating high human-vector contact. CONCLUSION: The study highlights the value of a multisectoral approach to outbreak responses, which resulted establishment of two new treatment centers in Kajiado, enhancing continuing access to care and associated surveillance. The study confirmed L. donovani and L. tropica as the causative agents for VL and CL, respectively, in Kajiado. The unusual co-occurrence of both forms complicates treatment and raises concerns about potential genetic recombination.