An outbreak of Leishmania major from an endemic to a non-endemic region posed a public health threat in Iraq from 2014-2017: Epidemiological, molecular and phylogenetic studies

Abstract

BackgroundCutaneous leishmaniasis (CL) is a neglected worldwide, zoonotic, vector-borne, tropical disease that is a threat to public health. This threat may spread from endemic to non-endemic areas. Current research has exploited epidemiological, molecular and phylogenetical studies to determine the danger of an outbreak of CL in the borderline area between northern and central Iraq from 2014–2017.Methodology/Principal findingsFor the first time, using sequence analysis of the cytochrome b gene, the occurrence of CL in the borderline area between northern and central Iraq was confirmed to be due to Leishmania major. The phylogenetic analysis indicated that it was closely related to the L. major MRHO/IR/75/ER strain in Iran.Conclusions and significanceIn conclusion, the genotype confirmation of the L. major strain will improve our understanding of the epidemiology of the disease. This is important for facilitating control programs to prevent the further spread of CL. Furthermore, this area could be considered as a model for further research on the risk of global CL epidemics in other non-endemic countries where both reservoir hosts and sandfly vectors are present.

A Clinicoepidemiological Study of Pediatric Cutaneous Leishmaniasis in Sinjar Province, Iraq

“…Leshmania major is the main genotype causing CL in Iraq. 15 The same genotypes were reported in Iran. 16 However, the cure rate in Iran ranged from 25% to 80%.…”

The Geographical Distribution of Cutaneous Leishmaniasis Causative Agents in Iran and Its Neighboring Countries, A Review

“…Moreover, the opening of the border between Iran and Iraq appears to have played an important role in the spread and the transmission of Leishmania strains between the two countries (128). High genetic similarity between a newly emerged Iraqi L. major strain and an Iranian strain support this hypothesis (101). As a vector-borne disease with two predominant vectors, P. papatasi (ZCL) and P. sergenti (ACL), and animal and human reservoirs, respectively, multiple factors will affect disease prevalence and epidemic proneness that will be favor one species over another or be common to both.…”

“…The civil war in Syria is a striking example with large numbers from highly CL endemic foci causing epidemics in neighboring countries, as well as the emergence of new foci of CL caused by nonindigenous Leishmania species. Similarly, since 2014 in Iraq, population displacement has led to CL outbreaks in non-endemic areas between north and central Iraq (101). CL is found more commonly in poor and marginalized populations due to a variety of factors that include small overcrowded poorly constructed dwellings with no screens on windows, poor nutritional status, lack of personal protection against insect bites, and the presence of garbage collection areas (141).…”

“…We could not find any phylogenetic studies of Iraqi L. tropica but it is likely that there are shared genotypes between eastern Iraq and western Iran. A genetic study of CL in Iraq identified L. major as the cause of a CL outbreak in the Garmian region in Sulaymaniyeh province from where there are no previous cases of CL (101). Garmian is close to Ghasr-e-Shirin county in Kermanshah province, Iran, a known focus of L. major (54).…”

Cutaneous leishmaniasis in Qasr-e Shirin, a border area in the west of Iran

“…In addition, Al-Bajalan et al . [12] observed that the incidence of CL was 27.5 per 100,000 populations, in a study carried out in Garmian area, Iraq, bordering with Iran. By active case detection, more CL cases may be identified since many patients never seek medical care.…”