The impact of refugees on leishmaniasis in Turkey: a new Syrian/Turkish Leishmania tropica population structure described by multilocus microsatellite typing (MLMT).

Turkey is one of the leishmaniasis endemic countries, and according to the recent reports, more than 45% of the cases were reported from the Southeastern part of Turkey. The disease is endemic in Syria with annually 25,000 cases, and it is emphasized by WHO that the actual number was estimated to be 2-5-fold higher than the reported numbers. Due to the civil war in Syria, more than seven million people were displaced and migrate to neighboring countries. The population structure of Leishmania tropica was investigated in the present study using clinical samples, which were obtained from Syrian patients residing in Turkey. Previously reported database was used to compare the results obtained in the present study. According to the multilocus microsatellite typing profiles, three populations (Şanlıurfa, Mediterranean, and Syrian/Turkish) were identified. Syrian/Turkish population, which is a new structure and identified for the first time in the present study, was comprised of clinical samples obtained from Syrian patients. The newly described population structure was homogeneous and solid comparing to previously identified population structures in Turkey. Further analyses revealed two sub-populations under the main Syrian/Turkish population structure. The findings of the present study revealed that the epidemiological status of leishmaniasis is more complicated than it is estimated. We believe that the data presented here will provide valuable information on the leishmaniasis epidemiology.