A new focus of cutaneous leishmaniasis caused by Leishmania tropica

OBJECTIVE: To determine the epidemiological status of the cutaneous leishmaniasis outbreak, isolation and identification of the parasite and preparation of a control program in a recently identified focus located in the Province of Yazd, Central Iran.

METHODS: This study was conducted in 124 classrooms of primary school children and among 139 households of an infected quarter in the city of Yazd during 1999-2000. All the students and members of the households were questioned and examined for the presence of ulcer(s) or scar(s). For each case a form was completed and necessary information were recorded. Smears were prepared from the edge of the ulcer and examined for the presence of amastigotes. Leishmania stocks from human lesions were isolated. Cultured promastigotes were identified using Random Amplified Polymorphic DNA-Polymerase Chain Reaction. Stray dogs were shot in the city and examined for the presence of any ulcer(s) or scar(s).

RESULTS: An endemic focus of cutaneous leishmaniasis caused by Leishmania tropica was detected in Yazd City, Central Iran. Examination of 3176 students aged 6-16 years old in 124 primary schools showed a rate of 0.7% for scars and 0.2% for active lesions. There was no significant differences between the sexes in the prevalence of active lesions or scars. A study of prevalence among 139 households with a total population of 572 persons in Darvazeh-Ghassabha quarter showed a prevalence of 13.5% for scars and 0.5% for ulcers. The most highly infected age group was 5-9 with a rate of 1.8%. Males and females were equally infected. Forty-six stray dogs were examined and none of them appeared to be infected.

CONCLUSION: According to this study, cutaneous leishmaniasis due to Leishmania tropica is endemic in the city of Yazd, Central Iran. Humans are considered to be the main reservoir and the transmission is believed to be from human to human by Phlebotomus sergenti. This focus now can be added to the list of anthroponotic cutaneous leishmaniasis foci in the country. Any residual insecticide spraying is not recommended during the next year due to the low prevalence of the disease.