Ghania Mezai

Cutaneous leishmaniasis (CL) caused by Leishmania major is a zoonotic disease transmitted by phlebotomine sand flies. Identification of reservoir hosts is critical for understanding transmission and guiding control. While Psammomys obesus and Meriones shawi are recognized reservoirs in North Africa, the role of other rodents remains unclear. We experimentally assessed the reservoir potential of Acomys cahirinus seurati from southeastern Algeria. Animals were intradermally infected, and clinical signs and infectiousness to sand flies were monitored. Parasite persistence in skin and visceral tissues was measured by quantitative PCR. All animals developed localized, self-limiting lesions. Seven of sixteen individuals transmitted parasites to Phlebotomus papatasi between 10 and 25 weeks post-infection. Parasites were mostly restricted to the inoculation site, with limited dissemination to contralateral pinnae and hindpaws, and rare presence in spleen or liver. Notably, some animals were infectious without visible lesions, indicating that ulceration is not required for transmission. These findings show that A. cahirinus seurati can maintain L. major infection for up to 6 months and transmit parasites to sand flies, fulfilling key criteria of a reservoir host. Thus, this species may contribute to CL transmission in endemic foci lacking classical reservoirs, emphasizing the need to consider alternative rodent hosts in surveillance and control programs in North Africa.