Some epidemiological aspects of cutaneous leishmaniasis with emphasis on vectors and reservoirs of disease in the borderline of Iran and Iraq

Cutaneous leishmaniasis in Iran: A review of epidemiological aspects, with emphasis on molecular findings

Leishmania parasites can cause zoonotic cutaneous leishmaniasis (CL) by circulating between humans, rodents, and sandflies in Iran. In this study, published data were collected from scientific sources such as Web of Science, Scopus, PubMed, Springer, ResearchGate, Wiley Online, Ovid, Ebsco, Cochrane Library, Google scholar, and SID. Keywords searched in the articles, theses, and abstracts from 1983 to 2021 were cutaneous leishmaniasis, epidemiology, reservoir, vector, climatic factors, identification, and Iran. This review revealed that CL was prevalent in the west of Iran, while the center and south of Iran were also involved in recent years. The lack of facilities in suburban regions was an aggravating factor in the human community. Some parts of southern Iran were prominent foci of CL due the presence of potential rodent hosts in these regions. Rhombomys opimus, Meriones lybicus, and Tatera indica were well-documented species for hosting the Leishmania species in Iran. Moreover, R. opimus has been found with a coinfection of Leishmania major and L. turanica from the northeast and center of Iran. Mashhad, Kerman, Yazd, and sometimes Shiraz and Tehran foci were distinct areas for L. tropica. Molecular identifications using genomic diagnosis of kDNA and ITS1 fragments of the parasite indicated that there is heterogeneity in leishmaniasis in different parts of the country. Although cutaneous leishmaniasis has been a predicament for the health system, it is relatively under control in Iran.

Leishmaniosis in Rodents Caused by Leishmania infantum: A Review of Studies in the Mediterranean Area

Leishmaniosis infection begins when a phlebotomine sand fly vector inoculates pathogenic protozoan parasites of the genus Leishmania into a mammalian host. In the case of Leishmania infantum, the domestic dog is considered to be the main parasite reservoir, and canine leishmaniosis (CanL) has a high mortality rate in untreated dogs. Hundreds of cases of human leishmaniosis (HL) are reported in the world each year, the incidence in Europe being relatively low. Leishmaniosis control is primarily focused on the dog, combining methods that prevent sand fly bites and boost host resistance to infection. However, these measures are only partially effective and new solutions need to be found. One of the main factors limiting CanL and HL control is the existence of a sylvatic Leishmania transmission cycle that interacts with the domestic cycle maintained by dogs. It is suspected that the main reservoir of infection in wildlife are rodents, whose expansion and rapid population growth worldwide is increasing the risk of human and zoonotic pathogen transfer. The aim of this review is therefore to analyze reports in the literature that may shed light on the potential role of rodents in the leishmaniosis transmission cycle in the Mediterranean area. Following the general methodology recommended for reviews, six databases (Google Scholar, Ovid, PubMed, Science Direct, Scopus and Web of Science) were explored for the period January 1995 to December 2020. The results extracted from 39 publications that met the established inclusion criteria were analyzed. It was found that 23 species of rodents have been studied in nine countries of the Mediterranean basin. Of the 3,643 specimens studied, 302 tested positive for L. infantum infection by serology, microscopy and/or molecular techniques.

Study of fauna, activity patterns and Leishmania infection rate of phlebotomine sand flies in Western Iran

Cutaneous leishmaniasis is a crucial vector-borne disease caused by various species of Leishmania and is transmitted by several species of sandflies. The present study was conducted to describe sand fly fauna on vectors of leishmaniasis and performing molecular identification of Leishmania isolates from them on the Iran-Iraq border. Entomological surveys were done from May to October 2016-2018 in 2 counties (Mehran and Dehloran) of Ilam province, west of Iran. Sandflies were collected by 40 Sticky Traps at each station. Samples were mounted for species identification using morphological characters of the head and abdominal terminalia. DNA was extracted from Phlebotomus papatasi females, and Leishmania isolates were identified through PCR on minicircle kDNA, followed by sequencing. A total of 5592 sandflies including 2 genera of Phlebotomus and Sergentomyia comprising 8 species of sand flies were detected. Leishmania major infection was detected in 3.33% of 300 tested female sandflies. Phlebotomus papatasi was predominant in outdoor and indoor resting places. Phlebotomus papatasi was determined as dominant vector of Leishmania major infection in Mehran and Dehloran counties, West of Iran. It seems the composition of sandfly species in the study area is almost similar to the other parts of Iran. A detailed description of the epidemiology and ecology of Phlebotomine sand flies needs to be established to accomplish effective vector control programs.

First molecular identification of Leishmania major in Phlebotomus papatasi in an outbreak cutaneous leishmaniasis area in Iraq

Cutaneous leishmaniasis (CL) is transmitted by Phlebotomine sand fly vectors, among which Phlebotomus papatasi is prevalent in Western Asia, Northern Africa and Southern Europe, and it is known as a vector for Leishmania major parasite in the world. However, in Iraq, morphological studies showed that P. papatasi is a predominant sand fly species and hypothesised to transmit CL causing Leishmania species including L. major and L. tropica. Few studies have found Leishmania species in sand flies in mixed pools of samples in this country. Accurate identification of sand flies as vectors of Leishmania species is required in Iraq. The current study aims to identify sand fly species, using both morphological and molecular phylogenetic analyses, in a region where CL tends to be endemic. Furthermore, molecular phylogenetic analysis has also used to confirm Leishmania species in the sand fly samples collected in 11 villages between Diyala and Sulaymaniyah Provinces. For the first time, we have found L. major in three individual sand flies, one engorged (with fresh blood meal) and two non-engorged (without visible fresh blood meal) P. papatasi females in an area of CL outbreaks since 2014-till now due to civil wars and internal conflicts happen in the region. Further study should be performed on sand fly population and Leishmania reservoirs in this region.

Prevalence of Leishmania major Yakimoff and Schokhor (Kinetoplastida: Trypanosomatidae) in Sandflies in Iran: A Systematic Review and Meta-Analysis

Cutaneous leishmaniasis is an important parasitic and vector-borne disease in Iran and can be transmitted to humans and animals through bites of infected female sand flies. The present study aimed to determine the pooled prevalence of Leishmania major in sand flies in Iran. A systematic review and meta-analysis was performed in the present study, so that databases, namely PubMed, Web of Sciences, Science Direct, ProQuest, Embase, Cochrane Reviews, and Scopus as well as IranDoc, SID, Elmnet, and Magiran were searched for finding Persian articles. Inclusion criteria of study contained the study in Iran and investigation of L. major parasite in sand flies. The quality of studies was examined by Joanna Briggs Institute Critical Appraisal Checklist for studies that reported prevalence data; and the data were analyzed by Stata 14 software. In total, 42 studies were evaluated, all of which had investigated the infection of Phlebotomus papatasi Scopoli (Diptera: Psychodidae). The infection of Phlebotomus caucasicus group was investigated in 13 studies, Phlebotomus ansarii Lewis in four studies, Phlebotomus salehi Mesghali and Rashti in five studies, and the infection of other species of sandflies in seven studies. According to the meta-analysis, the pooled prevalence of Ph. papatasi, Ph. caucasicus group, Ph. salehi, and Ph. ansarii were equal to 2.4, 6.2, 1.6, and 9.2%, respectively, with 95% confidence interval. According to reports of different rates of sand fly infection in different regions, all studies should have certain and standard forms and formats to determine the pooled prevalence of sand fly infection.