Zoonotic Cutaneous Leishmaniasis In Iran Research Articles

Application of Rodenticides for the Control of Zoonotic Cutaneous Leishmaniasis in Iran: A Systematic Review of the Literature

Introduction: Rodent control programs have a long history of controlling zoonotic cutaneous leishmaniasis (ZCL) in Iran. The present systematic review reports the effect of rodenticides in reducing ZCL in Iran. Materials and Methods: Various electronic databases were explored for reliable research using appropriate keywords between January 1970 and September 2023. Relevant studies were included based on the inclusion criteria. All articles identified from the systematic search were added into Endnote X9 (Clarivate Analytics) and duplicate articles were removed. This study followed standard procedures for systematic reviews and reported results according to systematic reviews guidelines. Results: Overall, 637 documents were identified after screening based on the PRISMA checklist, and finally, 13 papers were included in this systematic review. The findings indicated that most of studies used zinc phosphide (2.5%) and Klerat® mixed with wheat grains in rodents control programs in Iran. The results showed that rodent control programs were implemented in five provinces of Iran, including Esfahan, Yazd, Semana, Golestan, Kermanshah, and Fars, with the highest number of studies in Esfahan province. According to results, the incidence rate of ZCL significantly reduced after rodenticide implementation. Conclusion: This review study provides a better understanding of rodent control programs trends as a promising and practical approach to reducing ZCL incidence in Iran over the past 50 years and can serve as a reference for planning future control and research programs.

First Report of Natural Infection of Phlebotomus mongolensis to Leishmania major and Leishmania turanica in the Endemic Foci of Zoonotic Cutaneous Leishmaniasis in Iran.

The primary aim of this study is to determine infection to Leishmania parasites in the wild population of Phlebotomus caucasicus and Phlebotomus mongolensis using molecular methods in some important zoonotic cutaneous leishmaniasis foci in Iran. Sand flies were collected from active colonies of rodent burrows from 16 trapping sites using sticky trap paper. In order to detect and identify of Leishmania parasites in females Ph. caucasicus and Ph. mongolensis, the Nested-PCR amplification of ITS2-rDNA region was performed to generate amplicon with 245bp for Leishmania major, 206bp for L. gerbilli and 141bp for L. turanica. In the current study we found DNA of different gerbil parasites such as L. major and L. turanica, and mixed infection of L. major/L. turanica in Ph. caucasicus and Ph. mongolensis. It should be noted that, in Iran, natural infection with Leishmania parasites is recorded for the first time in this study in Ph. mongolensis. Both species of Ph. caucasicus and Ph. mongolensis not only may participate in the ZCL transmission cycle between reservoir hosts, but also results of this study support the role of these species as secondary vectors in the transmission of leishmaniasis to humans.

Molecular Detection of Leishmania Infection in Phlebotomine Sand Flies from an Endemic Focus of Zoonotic Cutaneous Leishmaniasis in Iran.

Due to the outbreak of zoonotic cutaneous leishmaniasis (ZCL), a disease caused by Leishmania major and mainly transmitted by Phlebotomus papatasi, in Damghan City, Semnan Province, the probable vectors of the disease were investigated in the city from 20 March 2016 to 20 January 2018. Sand flies were collected from indoors and outdoors biweekly by sticky traps in different parts of the city. The trapped sand flies were stored in 70% ethanol. They were identified and checked for Leishmania infections using nested-PCR method and specific primers; CSB1XR, CSB2XF, LiR, and 13Z. Overall, 1862 phlebotomine sand flies of Ph. papatasi (48.8%), Ph. andrejevi (8.3%), Ph. caucasicus (7.7), Ph. mongolensis (2%), Ph. sergenti (1.2%), Ph. alexandri (0.7%), Sergentomyia murgabiensis sintoni (29.3%), and Se. sumbarica (2%) were collected indoors (31.1%) and outdoors (68.9%). The highest and lowest numbers of collected sand flies were belonging to Ph. papatasi (48.8%) and Ph. alexandri (0.7%) respectively. 2.2% of the examined sand flies were shown to be infected with L. major and all were belonging to Ph. papatasi. This study confirms the report of Ph. papatasi infection with L. major and also the existence of Ph. sergenti and Ph. alexandri, the potential vectors of L. tropica and L. infantum respectively, in Damghan City. According to the findings, it is necessary for health officials to plan and take action to prevent the occurrence of ZCL epidemic in the city as well as the occurrence of other forms of leishmaniasis.

Anti Leishmanial Effect of Plantago psyllium (Ovate) and White Vinegar on Leishmania major Lesion in BALB/c Mice.

Leishmania major is the etiologic agent of zoonotic cutaneous leishmaniasis in Iran, and glucantime injection is currently used for its treatment. This study aimed to evaluate the anti-leishmanial effect of topical Plantago psyllium and white vinegar in L. major infected BALB/c mice. Thirty infected mice were divided into five groups as follows: Group 1: treated with the combination of ovata powder and white vinegar, Group 2: treated with glucantime, Group 3: treated with white vinegar, Group 4: treated with the combination of ovata powder and water, and Group 5: without any treatment. All the groups were treated for 18 days. Lesion size was measured, and final smears were prepared for microscopic examination. The findings indicated that the difference in the mean areas of the ulcers in all the groups before and after treatment was not significant, except for the second (glucantime) and third (vinegar) groups. Also, the results showed that in the first, second, third, and fourth group, 6 (60%), 4 (80%), 3 (60%), and 2 (40%) mice were healed, respectively. However, ulcers remained in all the five mice of the control group. The combination of ovata powder and white vinegar has been traditionally used to treat leishmanial lesions in Iran. It seems the most anti-leishmanial effect is related to vinegar and supported by Plantago. The route of treatment with this combination is very simple and painless in comparison with injection. Thus, further studies on this issue could help to design more effective and easy-to-use drugs.

The Effect of Geographical and Climatic Factors on the Distribution of Phlebotomus papatasi (Diptera: Psychodidae) in Golestan Province, an Endemic Focus of Zoonotic Cutaneous Leishmaniasis in Iran, 2014.

Background:Phlebotomus papatasi is known as the main vector of zoonotic cutaneous leishmaniasis. This study aimed to investigate the effect of geographical and bioclimatic factors on the Ph. papatasi distribution.Methods:A total of 34 villages were selected, and sampling was performed three times using 120 sticky traps in each selected village. All the collected species were mounted and identified their species. The densities of Ph. papatasi were measured in all the villages and entered into ArcMap as a point layer. The required bioclimatic and environmental variables were extracted from the global climate database and The normalized difference vegetation index was obtained from the MODIS satellite imagery, also, all variables entered into ArcMap as raster layers, so The numerical value of each independent variable in the cell where the selected village is located in this, was extracted using spatial analyst tools and the value to point submenu. All the data were finally entered into IBM SPSS, and the relationship was examined between the number of collected Ph. papatasi and the independent variables using Spearman’s correlation test.Results:A total of 1773 specimens of Ph. papatasi were collected. The findings of this study showed that max temperature of warmest month, temperature annual range, temperature seasonality, mean diurnal range, precipitation seasonality, mean temperature of driest and warmest quarter were positively associated with the density of Ph. papatasi.Conclusion:Air temperature and precipitation were shown as the most significant factors in the distribution of Ph. papatasi.

Climate change and its effect on the vulnerability to zoonotic cutaneous leishmaniasis in Iran.

Zoonotic cutaneous leishmaniasis (ZCL) is an important vector-borne disease with an incidence of 15.8 cases per 100,000 people in Iran in 2019. Despite all efforts to control the disease, ZCL has expanded into new areas during the last decades. The aim of this study was to predict the best ecological niches for both vectors and reservoirs of ZCL under climate change scenarios in Iran. Several online scientific databases were searched. In this study, various scientific sources (Google Scholar, PubMed, SID, Ovid Medline, Web of Science, Irandoc, Magiran) were searched. The inclusion criteria for this study included all records with spatial information about vectors and reservoirs of ZCL which were published between 1980 and 2019. The bioclimatic data were downloaded from online databases. MaxEnt model was used to predict the ecological niches for each species under two climate change scenarios in two periods: the 2030s and 2050s. The results obtained from the model were analysed in ArcMap to find the vulnerability of different provinces for the establishment of ZCL foci. The area under the curve (AUC) for all models was >0.8, which suggests the models are able to make an accurate prediction. The distribution of all studied species in different climatic conditions showed changes. The variables affecting each of the studied species are introduced in the article. The predicted maps show that by 2050 there will be more suitable areas for the co-occurrence of vector and reservoir(s) of ZCL in Iran compared to the current climate condition and RCP2.6 scenario. An area in the northwest of Iran is predicted to have suitable environmental conditions for both vectors and reservoirs of ZCL, although the disease has not yet been reported in this area. These areas should be considered for field studies to confirm these results and to prevent the establishment of new ZCL foci in Iran.

Comparative evaluation of salivary glands proteomes from wild Phlebotomus papatasi-proven vector of zoonotic cutaneous leishmaniasis in Iran.

BackgroundZoonotic Cutaneous Leishmaniasis is increasing in the world and Phlebotomus papatasi as a proven vector was considered in different aspects for disease control. Sandfly saliva contains proteins which provoke host immune system. These proteins are candidates for developing vaccines.ObjectivesThe main purpose of this research was comparing evaluation of salivary glands proteomes from wild P. papatasi. Extracting these proteins and purifying of original SP15 as inducer agent in vector salivary glands from endemic leishmaniasis foci were other objectives.MethodsAdult sandflies were sampled using aspirators and funnel traps from three endemic foci in 2017–2018. Each pair of salivary glands of unfed females was dissected and proteins were extracted using thermal shocking and sonication methods. Purification was performed through RP‐HPLC. All equivalent fractions were added together in order to reach sufficient protein concentration. Protein content and profile determination were examined with SDS‐PAGE.ResultsThe protein concentration of whole‐salivary glands of specimens was determined approximately 1.6 µg/µl (Isfahan) and 1 µg/µl (Varamin and Kashan). SDS‐PAGE revealed 10 distinct bands between 10 and 63 kDa. Analysis of proteomes showed some similarities and differences in the chromatograms of different foci. SDS‐PAGE of all collected fractions revealed SP15‐like proteins were isolated in 24 min from Varamin, 26 to 30 min from Kashan and 29.4 min from Isfahan and were around 15 kDa.ConclusionsIsolation of salivary components of Iranian wild P. papatasi is very important for finding potential proteins in vaccine development and measuring control strategy of zoonotic cutaneous leishmaniasis in Iran and this could be concluded elsewhere in the world.

The Effect of Climatic Change on the Current and Future Niche of Zoonotic Cutaneous Leishmaniasis Vector and Reservoir Species in Yazd Province

Introduction: Leishmania tropica and Leishmania major are the causative agents of Anthroponotic Cutaneous Leishmaniasis (ACL) and Zoonotic Cutaneous Leishmaniasis (ZCL) in various areas of Iran, respectively. Yazd province is one of the endemic centers of ZCL. Therefore, this study aimed to investigate and predict the effects of the climate change on the potential scattering of the vector and reservoir species of ZCL disease in Yazd province, as one of the endemic centers of ZCL in Iran in the present (1950-2000) and prospective time (2030). Materials and Methods: According to the findings of prior studies conducted in Yazd province, the data related to the vectors and reservoir of the ZCL were collected and recorded in the databank. ArcGIS 10.3 and MaxEnt software were used to estimate the suitable ecological niches using 19 variables. In this study, Beijing Climate Center Climate System Model and scenario of Representative Concentration Pathway 4.5 were applied with respect to 2030 horizon. Results: According to results of Jackknife test, the climate variables of Bio8 & Bio6 for the current period, and climate variables of Bio8 & Bio7 for the future (2030) produced the most effects on the distribution of vector and reservoir species in Yazd province. These results indicated that temperature had the greatest impact on the vector’s distribution in the present and future. Currently, eastern and central areas of the province are more likely to receive most of the vector and reservoir species. It is anticipated that in the future, we will observe an increase in the presence of vector in the western districts and reservoirs in the northern and central regions of the province. Conclusion: Climate conditions provide suitable habitats for easy transfer of ZCL disease in Yazd province. This research confirmed that suitable climatic conditions for the vector and reservoir will be expanded in coming years in comparison with the current period.

Morphometric discrimination between females of two isomorphic sand fly species, Phlebotomus caucasicus and Phlebotomus mongolensis (Diptera: Phlebotominae) in endemic and non-endemic foci of zoonotic cutaneous leishmaniasis in Iran

Objective: To delineate reliable morphological characteristics for identifying and separating female Phlebotomus caucasicus and Phlebotomus mongolensis which exist sympatrically in the main foci of zoonotic cutaneous leishmaniasis in Iran. Methods: Sand flies were collected using sticky trap papers from active colonies of rodent burrows installed from 16 catching sites. Morphometric measurements were analyzed of 87 Phlebotomus caucasicus and 156 Phlebotomus mongolensis. Univariate and multivariate analysis were carried out to determine significant morphometric variables for discrimination of the two species. Finally, seven morphological characteristics of 65 female Phlebotomus caucasicus and 124 female Phlebotomus mongolensis were described. Results: Univariate and multivariate analyses of 10 morphometric variables via Discriminant Function Analysis (DFA) and Principal Component Analysis (PCA) showed that five morphometric variables had an accuracy of 100% for discriminating female Phlebotomus caucasicus and Phlebotomus mongolensis. Moreover, PCA revealed that the five morphometric variables with the highest loadings separated these two species. Morphological studies on antennal flagellum (and its associated structures) and mouth-parts of female specimens demonstrated significant differences in several structures. Conclusions: The results show that morphological and morphometrical features can be used to discriminate two female isomorphic species, Phlebotomus caucasicus and Phlebotomus mongolensis accurately.

Ecological Niche Modeling of main reservoir hosts of zoonotic cutaneous leishmaniasis in Iran

Zoonotic cutaneous leishmaniasis (ZCL), caused by Leishmania major, is a common zoonotic vector-borne disease in Iran. Close contact with infected reservoir hosts increases the probability of transmission of Leishmania parasite infections to susceptible humans. Four gerbil species (Rodentia: Gerbillidae) serve as the main reservoir hosts for ZCL in different endemic foci of Iran. These species include Rhombomys opimus, Meriones libycus, Meriones hurrianae and Tatera indica; while notable infection has been reported in Nesokia indica as well. The purpose of this study is to model the distribution of these reservoirs to identify the risk areas of ZCL. A data bank was developed including all published data during the period of 1970–2015. Maximum entropy model was used to find the most appropriate ecological niches for each species. The areas under curve obtained were 0.961, 0.927, 0.922, 0.997 and 0.899, instead of 1, for training test in R. opimus, M. libycus, T. indica, M. hurrianae and N. indica, respectively. The environmental variable with the highest gain when used in isolation was slope for R. opimus and N. indica, annual mean temperature for M. libycus, and seasonal precipitation for T. indica and M. hurrianae. Summation of presence probabilities for three main species, i.e., R. opimus, M. libycus and T. indica revealed favorable ecological niches in wide areas of 16 provinces. This is the first study to predict the distribution of ZCL reservoir hosts in Iran. Climatology and topography variables had high contributions toward the prediction of potential distribution of the main reservoir species; therefore, as climate changes, the models should be updated periodically with novel data, and the results should be used in disease-monitoring programs.

Different Morphologies of Leishmania major Amastigotes with No Molecular Diversity in a Neglected Endemic Area of Zoonotic Cutaneous Leishmaniasis in Iran.

Background:Molecular diversity of Leishmania major and its morphological changes have become a controversial issue among researchers. Some aspects of polymorphic shapes of amastigotes in clinical manifestations along with molecular variation were evaluated among suspected patients of some exceptional zoonotic cutaneous leishmaniasis locations in Northern Khuzestan, Southwestern Iran. Methods:Suspected patients (n = 165) were sampled in zoonotic cutaneous leishmaniasis foci over two consecutive years during 2012-2014. Prepared smears were stained, scaled and measured by ocular micrometer. DNA was extracted from smears; ITS-rDNA and Cytochrome b (Cyt b) markers were amplified, and PCR products were digested by BsuR1 restriction enzyme. Then the RFLP and sequencing were employed. Results:Only L. major was identified in patients containing regular amastigotes' shapes (oval or round) with a size of 2-4 µm in each of classical wet, dry, mixed lesions. Meanwhile, irregular shapes (spindle, pear, or cigarette) were observed separately in non-classical wet lesions with more than 4 µm. Interestingly, a few amastigotes with an external flagellum were observed in some lesions. All sequenced ITS-rDNA and Cyt b genes of L. major did not show any molecular variation (χ 2 P > 0.05), including only one common haplotype (GenBank access no. EF413075). Conclusion:Findings proved that unlike other endemic foci, there is not a meaningful correlation between phenotypic and genotypic features of L. major isolates. This study is considered as the first comprehensive report to incriminate morphometric shapes of L. major amastigotes, which enhances our knowledge concerning their relevance with various clinical appearances and genotypic traits.

Diversity of Leishmania species and of strains of Leishmania major isolated from desert rodents in different foci of cutaneous leishmaniasis in Iran.

Zoonotic cutaneous leishmaniasis (ZCL) is a polymorphic disease which may show various symptoms. Genetic diversity of the parasite is suggested to be one of the factors influencing the clinical manifestation of the disease. This study used PCR for the detection and identification of leishmanial parasites at the species level and applied a multilocus microsatellite typing approach for investigating the genetic diversity of Leishmania major isolated from captured rodents in two foci of ZCL in Iran: Turkemen Sahara and Fars province. ITS1-rDNA amplification and subsequent RFLP analyses were performed using DNA extracted from the rodents' ears. Approximately one third of the rodents tested positive for Leishmania; in all rodents L. major was the predominating infecting agent. Seven Rhombomys opimus were positive for L. turanica DNA and one for both L. major and L. turanica. DNA of L. infantum was identified in one Rh. opimus. Seventeen strains of L. major, 15 from Turkemen Sahara and two from Fars province, isolated from different rodents were tested for variation at nine polymorphic microsatellite loci. Ten different MLMT genotypes were observed. They were compared to 89 previously published microsatellite profiles obtained for strains of L. major of different geographical origin. Bayesian model-based and genetic distance based approaches confirmed that strains from Turkemen Sahara and from Fars are genetically different and belong to different genetic groups, largely corresponding to their geographical origins. The considerable genetic variability of L. major might be related to differences in reservoir host and/or to the existence of different populations of the vector, Phlebotomus papatasi.

Novel identification of Leishmania major in Hemiechinus auritus and molecular detection of this parasite in Meriones libycus from an important foci of zoonotic cutaneous leishmaniasis in Iran

One of the well-known foci of zoonotic cutaneous leishmaniasis (ZCL) in Iran is Turkemen Sahara, which is located in north eastern Iran. ZCL is a disease of mammals, and humans can become infected as accidental hosts. Many researchers have argued that Rhombomys opimus is the only main reservoir host of ZCL in this region of the Golestan province. No other rodents or mammals are thought to host or have been reported to host Leishmania parasites in this region. This research was designed and developed to isolate, detect and firmly identify Leishmania parasites in mammals and rodents other than R. opimus. Wild mammals were caught from gerbil burrows. Leishmania parasites were detected to assess the infection of reservoir hosts in 2010. Each genomic DNA sample was screened for Leishmania infection via nested PCR and sequencing using the internal transcribed spacer ribosomal DNA (ITS-rDNA) identification protocol for parasites. The greatest number of infections (8/19) were found in Meriones libycus. One in three infections was found in Hemiechinus auritus, and this is the first report of infection in this species. Only Leishmania major was definitively identified and unambiguously typed in M. libycus and H. auritus. The infection rates in these two wild mammals were not significantly different, and no other gerbil parasites were detected in M. libycus or H. auritus at our study site. Recent findings of Leishmania turanica in R. opimus and failures to detect L. turanica in M. libycus may be attributable to unidentified Leishmania infections in two M. libycus due to unreadable sequences. These cases may represent mixed infections by L. major and L. turanica. The assumptions that gerbil parasites can be co-infectors provide a starting point for the identification of the causative and potential parasites responsible for the frequent infections that are mainly mediated via sandfly vectors.

Performance of an ELISA and indirect immunofluorescence assay in serological diagnosis of zoonotic cutaneous leishmaniasis in iran.

Serological assays have been extensively evaluated for diagnosis of visceral leishmaniasis (VL) and considered as a routine method for diagnosis of VL while these methods are not properly evaluated for diagnosis of cutaneous leishmaniasis (CL). This study aimed to assess the performance of indirect immunofluorescent-antibody test (IFA) and enzyme-linked immunosorbent assay (ELISA) for serodiagnosis of cutaneous leishmaniasis in Iran. Sixty-one sera samples from parasitologically confirmed CL patients and 50 sera from healthy controls along with 50 sera from non-CL patients were collected. Antigen was prepared from promastigotes and amastigotes of Leishmania major. IFA was used to detect anti-Leishmania IgG while ELISA was used to detect anti-Leishmania IgM, total IgG, or IgG subclasses (IgG1 and 4). ELISA, for detection of total IgG and IgM, showed sensitivity of 83.6% and 84.7% and specificity of 62.7% and 54.6%, respectively. Sensitivity and specificity of ELISA for detecting IgG1 and IgG4 were 64%, 75% and 85%, 49%, respectively. Sensitivity and specificity of IFA were 91.6% and 81%. Conclusion. Findings of this study demonstrated that serological test, especially IFA, can be used for proper diagnosis of CL.

Molecular characterization of Leishmania spp. in reservoir hosts in endemic foci of zoonotic cutaneous leishmaniasis in Iran

Zoonotic cutaneous leishmaniasis (ZCL) is an expanding disease and a public health issue in Iran. In the present study, rate of natural infection of rodent populations with Leishmania was investigated in six endemic foci including 28 villages in Golestan, Esfahan, Yazd, Fars, Khuzestan and Ilam provinces. A total of 593 rodents were captured and identified as Rhombomys opimus (n = 325), Meriones libycus (n = 171), Meriones persicus (n = 27), Tatera indica (n = 37), Nesokia indica (n = 12), Rattus rattus (n = 13) and Mus musculus (n = 8). Microscopic examinations of Giemsa-stained smears showed that 108 out of 593 (18.2%) rodents were infected with Leishmania spp., whereas infection of 186 out of 593 (31.4%) rodents with Leishmania was then confirmed by ITS1-PCR. The highest rate of infection was found in R. opimus (prevalence of 35%) and M. libycus (31%). Based on Restriction Fragment Length Polymorphism (RFLP), 145 (78%) of 186 samples detected as Leishmania DNA were identified as L. major, 8 (4%) samples as L. turanica and 33 (18%) as mixed infection (L. major and L. turanica). Samples from infected rodents were inoculated subcutaneously at tail base of BALB/c mice. In 35 of them, nodules and ulcers containing amastigotes appeared at the inoculation site. The samples prepared from infected rodents were cultured in NNN medium and only two samples werepositive. Rhombomys opimus, M. libycus, M. persicus, T. indica and N. indica were confirmed as reservoir hosts of ZCL in the studied regions. Leishmania major infection was usually accompanied L. turanica in naturally infected gerbils (R. opimus and M. libycus) in Golestan, Esfahan and Fars provinces.

A molecular and parasitological survey on cutaneous leishmaniasis patients from historical city of Kashan in Isfahan province, center of Iran

ObjectiveTo study cutaneous leishmaniasis (CL) for identifying the dominant Leishmania species on CL patients referred to medical health centers of historical Kashan city and suburbs located in Isfahan province in central part of Iran during 2010 to 2011. MethodsFrom 137 CL cases, were microscopically positive, the skin lesion serosity materials of 103 cases were cultured in monophasic culture media (RPMI 1 640). We used the PCR-RFLP method for characterization the Leishmania isolates, by using specific internal transcribed spacer (ITS1) primers and HAEШ as the restriction fast enzyme. DNA was extracted from 63 samples. ResultsL. tropica is main species in 58 (92.1%) cases and L. major is identified in 5 (7.9%) cases. Indeed randomly two isolates were the species characterized as L. major produced ulcer at the base tail of BALB/c mice after 3 weeks but from three L. tropica isolates none of them produced any lesion during 6 months post inoculation. ConclusionsThe parasitological, epidemiological aspect and molecular methods of this study showed that, Kashan and suburb are anthroponetic CL area despite this city located in Isfahan province as an ancient focus of zoonotic CL in Iran.

Baseline susceptibility of a wild strain of Phlebotomus papatasi (Diptera: Psychodidae) to DDT and pyrethroids in an endemic focus of zoonotic cutaneous leishmaniasis in Iran

Phelebotumus papatsi is considered to be the main vector of zoonotic cutaneous leishmaniasis as well as sand fly fever in Iran. There are several measures for vector control, with emphasis on insecticides. The objective of this study was to determine the baseline susceptibility of this vector to the commonly used insecticides in an endemic focus of the disease in central Iran. P. papatasi collected from the field were used for susceptibility status. Its baseline susceptibility to DDT and pyrethroids was assessed on about 6866 specimens collected from Badrood rural district, Esfahan Province, Iran, during the summer of 2010. The LT(50) and LT(90) values were measured according to the World Health Organisation (WHO) test using probit analysis and regression lines. Results of tests against female P. papatasi revealed LT(50) values to DDT 4%, permethrin 0.75%, deltamethrin 0.1%, cyfluthrin 0.15% and lambdacyhalothrin 0.05% of 1104.97, 182.35, 26.79, 15.42 and 1.48 s respectively. The figures for male P. papatasi were 973.51, 59.5, 4.4, 2.65 and 1.5. The results of this study provide a guideline for implementation of different vector control measures. Furthermore, guidelines are needed for monitoring and evaluation of insecticide susceptibility tests against sand flies.

Mitochondrial DNA diversity in the populations of great gerbils, Rhombomys opimus, the main reservoir of cutaneous leishmaniasis

Accurate identification of animal reservoirs of transmissible diseases is an absolute requirement to any epidemiological survey of zoonoses and is essential for predicting species-specific population outbreaks and therefore to develop accurate ecological control strategies. The systematic status of the great gerbil (Rhombomys opimus) remains unclear, despite the fundamental role of these rodents as the main known reservoir hosts of the protozoan parasite Leishmania major in the epidemiology of zoonotic cutaneous leishmaniasis (ZCL) in central and south Asia. In the present work, we represent molecular evidence supporting the identification of at least two major lineages (subspecies) within the species of R. opimus in Iran. Analysis of the mitochondrial cytochrome b (cyt b) gene, revealed a range of 1–10% genetic variation among populations, which were well associated with biogeographic origins and subspecies. Results of laboratory cross hybridization between the subspecies and finding sympatric haplotypes of the two subspecies suggested that no pre- or post-zygotic barriers exist between the subspecies indicating that they still belong to a single taxon. However, the amount of genetic variations between populations/subspecies is high enough to lead them to speciation in future. Implications of such findings on the eco-epidemiology of ZCL in Iran are discussed.

Dynamics of Leishmania infection rates in Rhombomys opimus (Rodentia: Gerbillinae) population of an endemic focus of zoonotic cutaneous leishmaniasis in Iran

Zoonotic cutaneous leishmaniasis (ZCL) due to Leishmania major is a great public health problem in the Old World. Leishmania major is widely distributed in populations of rodents in arid and savannah regions. In this study, seasonal variation of natural infection with Leishmania parasites in Rhombomys opimus (Rodentia: Gerbillinae) population of an endemic focus of ZCL in Iran was monitored. The study was conducted from October 2007 to October 2008 in the central part of the country. Nested polymerase chain reaction (PCR) assay was used for the detection and identification of Leishmania parasites, and the results were confirmed by PCR-restriction fragment length polymorphism (RFLP). The results showed that Leishmania infection rate was 55.8% (29 out of 52 gerbils) using nested PCR. The highest and lowest Leishmania infection rates were observed in fall and summer, respectively. Gerbils that were found to be infected only with L. major were 5.8%, and that with Leishmania turanica were 23.1%. A mixed natural infection was seen in the rodents with L. major and L. turanica (21.2%), with L. major and L. gerbilli (1.9%), and with all the three species (3.9%). Leishmania major infection alone was seen in fall and winter whereas mixed infection of L. major and L. turanica was observed in all seasons except in summer. Leishmania turanica infection was observed throughout the year. It is concluded that L. major, L. gerbilli, and L. turanica circulate in the population of R. opimus in central part of Iran. Leishmania major infection is usually accompanied by L. turanica in naturally infected gerbils with the highest rate in fall. It is recommended that the role of L. turanica in the epidemiology and transmission of ZCL should be reconsidered.

A randomised, double-blind, controlled trial of a killed L. major vaccine plus BCG against zoonotic cutaneous leishmaniasis in Iran

Safety and efficacy of killed (autoclaved) L. major promastigotes, ALM, mixed with BCG against zoonotic cutaneous leishmaniasis was tested in healthy volunteers (n=2453) in a randomized double blind trial vs. BCG as control. Side-effects were similar in both groups but tended to be slightly more frequent and prolonged in the ALM+BCG group. Leishmanin skin test conversion (induration ≥5 mm) was significantly greater in the ALM+BCG than in the BCG group (36.2% vs. 7.9% on day-80 and 33% vs. 19%, after 1 year, respectively). Cumulative incidence rates for 2 years, were similar in both groups (18.0% vs. 18.5%). However, LST responders on day 80 (≥5 mm) had a significantly lower incidence (35%) of CL during the first year than non-responders. A single dose of ALM+BCG is not sufficiently immunogenic to provide a measurable response when compared to BCG alone. A single dose of this vaccine has been shown to be safe with no evidence of an exacerbating response following natural infection; hence, multiple doses or other adjuvants should be considered to increase its immunogenicity.