Molecular Identification of Leishmania Species in an Outbreak of Re-Emerged Cutaneous Leishmaniasis in Southwestern Iran During 2015 - 2016

Dezful and its suburbs, as the second city in Khuzestan Province, southwest of Iran, has been an endemic area of cutaneous leishmaniasis (CL) with a low incidence rate since the last decades. However, the disease incidence has rapidly increased, and now is considered as a re-emerging parasitic disease in the area.

The aim of this study was to identify the most prevalent CL species in Dezful Region.

A total of 196 microscopically confirmed slides from CL patients referred to Dezful Health Center were randomly collected in the period of 2015 - 2016. After DNA extraction from microscopically positive slides, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was carried out on 61 eligible specimens using ribosomal internal transcribed spacer 1 (ITS1) gene. The HaeIII restriction enzyme was used for the identification of species.

Samples were randomly collected from 196 acute CL cases, including 110 (56.2%) males and 86 (43.8%) females. Most infections were seen in the age range of 2 - 7 years (65/196, 33.1%). Totally, 60.1% of the cases had only one lesion, and half of the lesions appeared on hands. Furthermore, 162 (82.7%) cases were referred to Dezful Health Center in the cold seasons (autumn and winter). Results of PCR-RFLP on 61 eligible isolates showed that 60 (98.4%) isolates were Leishmania major, and only 1 (1.6%) isolate was Leishmania tropica.

Our findings indicated that L. major is the main agent of re-emerged CL in Dezful and its suburbs, and the disease is a zoonosis.