Reemergence of zoonotic cutaneous leishmaniasis in an endemic focus, northeastern Iran

Zoonotic cutaneous leishmaniasis (ZCL) is a form of disease, which is mostly caused by Leishmania major (L.major) in the Old World with high incidence through early life. Recently, the high incidence of CL has been reported in Jajarm County, northeastern Iran. The aim of the present study was to investigate the epidemiological aspects of CL and to identify Leishmania spp. in the area. Between 2012 and 2018, patients with active lesions suspected of CL were examined. Diagnosis was performed by methods of clinical examination and direct smears. Conventional kDNA polymerase chain reaction (PCR) was used to identify species of Leishmania. During the seven-year study period, 629 subjects were diagnosed as CL cases by clinical and microscopic examination. Considering the population of the study area, the average incidence rate was 237.8 per 100,000 population. Most (29.4%) of the subjects with ZCL were aged <10 years. Most of the patients (58.7%) were male and the rest were female. Most ulcers were observed on the face (32.2%) and hands (23.7%), respectively. Most patients (90%) had two or more ulcers on their body. The highest incidence was in the autumn in October (32%). Our data revealed that an ongoing reemergence of ZCL focus caused by L.major has arisen in the study area. Moreover, direct PCR on the smears for identifying Leishmania showed 100% specificity, and the species was identified as L. major using species -specific kDNA PCR. The use of conventional PCR on skin smears seems to provide a valuable method for confirming the clinical diagnosis of ZCL, which is very specific and sensitive particularly for clinical correlative studies. Further investigations are needed to improve planning strategies of vectors and reservoirs populations.