Molecular Detection of Leishmania spp. in Negative Smears of Patients with Cutaneous Leishmaniasis in Bam, Southeast Iran

There are various clinical forms of cutaneous leishmaniasis (CL) and there is lack of access to diagnostic local laboratories especially in endemic regions. The present study aimed to conduct molecular examination of the typical and atypical clinical forms of CL in endemic area of Bam, Iran. This cross-sectional study was carried out between 2013 and 2014. The diagnosis was performed by direct smears from skin lesions, Giemsa staining, and microscopic examination. Total DNA was extracted from positive and negative direct smears. PCR method was used to determine the genus and species of Leishmania.  In this study, 353 suspected cases of CL in Bam Health Center were investigated of whom 278 (78.7%) were positive by microscopic examination. Forty skin smears from typical lesions were positive by both PCR and microscopic examinations, but out of 40 skin smears from atypical lesions which were negative by microscopic observation, Leishmania DNA was detected in 6 (15%) samples. Leishmania tropica was identified in all positive samples. In current study, microscopy method was not found reliable enough for diagnosis of CL. Therefore, for early diagnosis of the disease PCR is recommended in negative smears of patients suspected of CL.