Epidemiological study in a new focus of cutaneous leishmaniosis due to Leishmania major in Ardestan town, central Iran.

An endemic focus of zoonotic cutaneous leishmaniosis caused by Leishmania major zymodeme MON-26 was identified in Ardestan town central Iran, during 1998-99. Among 1960 school children examined over a 1-year period of time, 0.92% had evidence of active lesions and 1.53% had scar indicative of past infection. The incidence of the disease among school children was 3.2 per thousand in 1998. In a separate study, the incidence of infection among 100 households in an area with a population of 460 persons showed 3.26% for scars and 1.3% for ulcers. The most highly infected age group was 10-14 with a rate of 2.74%. Meriones libycus (93.3%) and Nesokia indica (6.7%) were present around the town of Ardestan. Both were found to be infected with Leishmania. Two out of 28 M. libycus (7.1%) and one out of two N. indica had positive results. M. libycus is probably the principal reservoir host of zoonotic cutaneous leishmaniosis in this area. Fourteen dogs appeared to be uninfected because examination showed no active lesion or scar. Most probably Phlebotomus papatasi is the vector because about 93% of indoor sandflies were of this species. The active season of sandflies was from late May to late October. Economic changes in this area of Iran may have contributed to this outbreak of cutaneous leishmaniosis.