The PCR-based detection of Leishmania major infections in Meriones libycus (Rodentia: Muridae) from southern Iran.

Cutaneous leishmaniasis (CL) is an increasing public-health problem in the countries of the Mediterranean region. In southern Iran, for example, the incidence of CL has more than doubled over the last decade. As part of an investigation of this worrying trend, the leishmanial infections of the wild rodents that may act as reservoir hosts were investigated in the Iranian province of Fars. Overall, 82 rodents, 56 of them Libyan jirds (Meriones libycus), were collected, in live traps, from a new, hypo-endemic focus of zoonotic CL. When Giemsa-stained smears of ear tissue or any lesions on the rodents were prepared and checked under a light microscope, amastigotes were found in the smears from six of the rodents, all M. libycus. None of the other rodents investigated was found to be infected. The infected rodents were encountered in two of the three areas studied. In PCR-based assays, the amastigotes seen in the ear smears and those from two recent human cases of CL from the focus were all found to be identical to a reference strain of L. major. It therefore seems that M. libycus is the main active reservoir host for ZCL in the focus.