The existence of only one haplotype of Leishmania major in the main and potential reservoir hosts of zoonotic cutaneous leishmaniasis using different molecular markers in a focal area in Iran

A Systematic Review (1990-2021) of Wild Animals Infected with Zoonotic Leishmania

Leishmaniasis are neglected diseases caused by several species of Leishmania that affect humans and many domestic and wild animals with a worldwide distribution. The objectives of this review are to identify wild animals naturally infected with zoonotic Leishmania species as well as the organs infected, methods employed for detection and percentage of infection. A literature search starting from 1990 was performed following the PRISMA methodology and 161 reports were included. One hundred and eighty-nine species from ten orders (i.e., Carnivora, Chiroptera, Cingulata, Didelphimorphia, Diprotodontia, Lagomorpha, Eulipotyphla, Pilosa, Primates and Rodentia) were reported to be infected, and a few animals were classified only at the genus level. An exhaustive list of species; diagnostic techniques, including PCR targets; infected organs; number of animals explored and percentage of positives are presented. L. infantum infection was described in 98 wild species and L. (Viania) spp. in 52 wild animals, while L. mexicana, L. amazonensis, L. major and L. tropica were described in fewer than 32 animals each. During the last decade, intense research revealed new hosts within Chiroptera and Lagomorpha. Carnivores and rodents were the most relevant hosts for L. infantum and L. (Viannia) spp., with some species showing lesions, although in most of the studies clinical signs were not reported.

Epidemiology, Associated Factors and Treatment Methods of Cutaneous Leishmaniasis Based on Previous Data from 2013 to 2018 in Ilam, Western Iran

OBJECTIVE

The aim of this study was to evaluate the epidemiology, clinical presentation and types of treatment of cutaneous leishmaniasis (CL) in the province of Ilam (Western Iran) in 5 years (from May 2013 to January 2018). This cross-sectional study involved patients diagnosed with CL who were referred to Mehran City Health center.

METHODS

All patients were diagnosed by clinical and parasitological (Giemsa staining of lesion to observe the parasite) methods. Moreover, a structured questionnaire on demographic data including age, sex, occupation, number and site of the lesions, treatment regimen was administered to each case.

RESULTS

In total, 2001 positive CL cases were observed in this study. The highest prevalence of CL was reported in the autumn season and mainly among male subjects residing in urban communities. The prevalence of CL varied with the age group: higher in the age group of 1-10 years than other groups. Besides, hands and faces were the most affected regions of the body. Most of the cases (47.35%) were managed by topical treatment (glucantime) and cryotherapy followed by systemic treatment (pentavalent antimony) 26.85%.

CONCLUSIONS

The prevalence of disease varied with age, increasing the prevalence rate in children due to their habitats, the highest prevalence in autumn due to climatic conditions. These findings help to better discuss the prevention and treatment of infections.

Molecular characterization of Theileria spp. in livestock and the first report on the occurrence of Theileria sp. OT3 in Iran

Theileria lestoquardi, T. ovis, and T. annulata are recognized as major causative agents for ovine and cattle theileriosis in Iran, respectively. Recently, there have been reports on the presence of Theileria spp. (Theileria sp. OT1, Theileria sp. OT3, and Theileria sp.). In this study, 37 blood samples were collected from sheep and cattle with clinically suspected Theileria infection in the Northwest of Iran. The samples were analyzed using a light microscope. DNA samples were amplified via nested-polymerase chain reaction (PCR) of 18S rRNA gene. The amplicons were digested with HpaII, following restriction fragment length polymorphism (RFLP) and sequenced to reconfirm Theileria species. The microscopic examination indicated that 4 out of 37 (10.8%) blood samples were infected with Theileria spp. Based on the nested PCR-RFLP and sequencing data, 5.4%, 13.5%, and 27% of blood samples were infected with Theileria sp. OT3, T. ovis, and T. annulata, respectively. The pairwise distance matrix of Theileria sp. OT3 showed 99.8-100% identity and 0-0.2% divergence in comparison with the registered sequences. The present study is the first report of Theileria sp. OT3 in Iran. To the evaluate evolution of Theileria spp. and providing resultant genetic data, further research with a larger sample is necessary in the region.

Predominance of Leishmania major and rare occurrence of Leishmania tropica with haplotype variability at the center of Iran

BACKGROUND

Leishmania major is a causative agent of zoonotic cutaneous leishmaniasis in the center of Iran, Abarkouh district. Molecular characterization and precise incrimination of Leishmania species was carried out to perform controlling measurements and to design treatment programs for zoonotic cutaneous leishmaniasis.

METHODS

All smears isolated from ulcers of suspected patients were examined under a light microscope and graded for amastigotes frequency. Extraction of DNA, PCR, RFLP and sequencing of ITS-rDNA genotype were done to increase the efficacy of Leishmania parasites identification at their species-specific level and to detect any Leishmania infections within.

RESULTS

Humans were found to be infected with L. major with high infection frequency and also Leishmania tropica was identified with low occurrence for the first time as non-native species using molecular analyses. The rates of infections was considerable with microscopic observation (n = 65, 73%) out of 89 smears prepared from suspected patients. Molecular analyses showed that the density of L. major was significantly higher (n = 48, 53.93%) than L. tropica (n = 4, 4.49%) (Mann-Whitney U test: p < 0.05) and two samples (2.25%) remained ambiguous after several sequencing. L. major did not have diversity with two common haplotypes but L. tropica were found to exhibit high diversity with three novel haplotypes.

CONCLUSION

L. major was considered the causative agent of leishmaniasis in the region, but the identification of a non-native L. tropica revealed the importance of further isolation of Leishmania parasites following molecular analyses and confirmation, and also revealed the importance of further isolation of Leishmania parasites from patients of the field areas who do not have easily access to health care centers for specialized treatment strategies.

Sandflies species composition, activity, and natural infection with Leishmania, parasite identity in lesion isolates of cutaneous leishmaniasis, central Iran

Zoonotic cutaneous leishmaniosis (ZCL) is a crucial public health challenge in Iran. Sandflies feed on reservoir rodents' blood infected with Leishmania parasite and transmit it to other hosts. This study was conducted to find out the composition and monthly activity of sandflies as well as to identify the protozoan pathogens (Leishmania/Crithidia) by polymerase chain reaction (PCR) in an emerging ZCL focus of Abarkooh, Yazd province, Iran, in 2016. A cross-sectional study was done in rural areas of Abarkooh. From April to November 2016, sticky traps were used indoor and outdoor to capture sandflies once every fortnight. Their composition and monthly activity were recorded. Following identification of sandflies and DNA extraction from them, PCR was used to identify their parasite and match it against samples taken from ZCL confirmed and suspected patients' lesions. After collection, a total of 2045 sandflies (779 indoor, 1266 outdoor) were identified to species level. Sandfly activity started early April in this area with two active peaks (one late May and the other late August) terminated about mid-November. Seven Phlebotomus species and three Sergentomyia species were identified. The most and the least abundant species were P. papatasi (40.1%) and P. alexandri (0.09%), respectively. Using PCR, only 6% (12:200) of P. papatasi sandflies were infected with Leishmania parasite. No Crithidia was detected in either sandflies or human lesions (176 specimen). Based on the highest abundance both indoor and outdoor of P. papatasi, this sandfly was considered the main vector of ZCL in this area. The capture of P. caucasicus, P. mongolensis, and P. ansarii from rodent burrows showed these species were likely involved in pathogen transmission in reservoir rodents' burrows.

Rodent-borne diseases and their public health importance in Iran

Background

Rodents are reservoirs and hosts for several zoonotic diseases such as plague, leptospirosis, and leishmaniasis. Rapid development of industry and agriculture, as well as climate change throughout the globe, has led to change or increase in occurrence of rodent-borne diseases. Considering the distribution of rodents throughout Iran, the aim of this review is to assess the risk of rodent-borne diseases in Iran.

Methodology/Principal finding

We searched Google Scholar, PubMed, Science Direct, Scientific Information Database (SID), and Magiran databases up to September 2016 to obtain articles reporting occurrence of rodent-borne diseases in Iran and extract information from them. Out of 70 known rodent-borne diseases, 34 were reported in Iran: 17 (50%) parasitic diseases, 13 (38%) bacterial diseases, and 4 (12%) viral diseases. Twenty-one out of 34 diseases were reported from both humans and rodents. Among the diseases reported in the rodents of Iran, plague, leishmaniasis, and hymenolepiasis were the most frequent. The most infected rodents were Rattus norvegicus (16 diseases), Mus musculus (14 diseases), Rattus rattus (13 diseases), Meriones persicus (7 diseases), Apodemus spp. (5 diseases), Tatera indica (4 diseases), Meriones libycus (3 diseases), Rhombomys opimus (3 diseases), Cricetulus migratorius (3 diseases), and Nesokia indica (2 diseases).

Conclusions/Significance

The results of this review indicate the importance of rodent-borne diseases in Iran. Considering notable diversity of rodents and their extensive distribution throughout the country, it is crucial to pay more attention to their role in spreading infectious diseases for better control of the diseases.

This review showed that approximately half of the known rodent-borne diseases have been reported in Iran, half of which were reported both in humans and rodents. Most of the diseases were bacterial and parasitic. Plague, leishmaniasis, and hymenolepiasis were the most frequent diseases among rodent populations. Also, this review showed that among the rodent species, three commensal ones—R. norvegicus, M. musculus, and R. rattus—play an important role in the transmission of diseases to humans in Iran. Considering repeated reports of many of these diseases in humans and rodents, and the notable diversity and extensive distribution of rodents throughout Iran, it is crucial to pay adequate attention to rodents as a source of zoonotic infectious diseases in the country.

Prevalence of Leishmania species in rodents: A systematic review and meta-analysis in Iran

Leishmaniasis are diverse group of diseases caused by numerous species of genus Leishmania. Herein we have contrived a systematic review and meta-analysis on the prevalence of Leishmania species in rodents of Iran. For this purpose, following the general methodology recommended for systematic reviews and meta-analysis, six English databases (PubMed, Science Direct, Scopus, Ovid, Web of Science and Google Scholar) and four Persian databases (Magiran, SID, Iran Doc and Iran Medex) were explored during January 1995 till June 2015. Papers were selected based on 8 pre-defined inclusion criteria. During the years, a total number of 4485 different rodents were captured; among which 1291 cases were Leishmania positive. The calculated weighted prevalence of Leishmania species in rodents was 23% (95% CI=18-28). Given geographical zones of Iran, the highest and lowest prevalence rate was belonged to North 50% (95% CI=40-61) and West 11% (95% CI=5-17), respectively. Rhombomys opimus (1766), Meriones lybicus (1258) and Tatera indica (488) were the three most abundant captured rodents, while the highest prevalence of Leishmania species was observed in Nesokia indica 48% (95% CI=42-54) and followed by R. opimus 39% (95% CI=30-47). Egger's regression test was performed to detect publication bias, which revealed it may not have a significant influence on overall weighted prevalence estimate (P=0.317). Meta-regression analysis demonstrated that there is no significant relationship between overall prevalence with sample size (P=0.1) and year of publication (P=0.7). The results showed remarkable prevalence of Leishmania species in rodent reservoirs. In future, adopting a suitable strategy for control and combat with rodents is necessary.