Cutaneous leishmaniasis: an epidemiological study in southwest of Iran

Phylogenetic insights into Leishmania species circulating among humans, vectors, and reservoir hosts in Shiraz, Southern Iran: implications for leishmaniasis control

Leishmaniasis remains a significant public health challenge in southern Iran, particularly in the Fars province, where Shiraz is a major focus of the disease. This study aimed to elucidate the phylogenetic relationships of Leishmania species isolated from humans, sand flies, and reservoir hosts in Shiraz and its suburbs. Cutaneous slit biopsies were collected from 350 suspected human cases of cutaneous leishmaniasis (CL), and samples were also obtained from rodents (Tatera indica) and sand flies (Phlebotomus papatasi). Parasites were cultured, and DNA was extracted for PCR amplification of the minicircle kinetoplast DNA (kDNA) gene. Phylogenetic analysis was performed using Neighbor-Joining and Maximum Likelihood methods. The results revealed the presence of Leishmania major, L. tropica, and L. infantum, with L. major being the predominant species. Phylogenetic trees demonstrated high genetic similarity between local isolates and those from other regions, including Iran, the UK, and Spain. This study highlights the complex transmission dynamics of Leishmania in Shiraz and underscores the need for targeted control strategies. The findings contribute to a deeper understanding of the genetic diversity and evolutionary relationships of Leishmania species in endemic regions.

qPCR as a Tool for the Diagnosis of Visceral and Cutaneous Leishmaniasis: A Systematic Review and Meta-Analysis

INTRODUCTION

Ensuring accuracy in the diagnosis of leishmaniasis is crucial due to the myriad of potential differential diagnoses. Given the inherent limitations of serological techniques, real-time polymerase chain reaction (qPCR) emerges as a superior alternative. Furthermore, parasitological methods, conventionally regarded as the gold standard owing to their high specificity, encounter challenges concerning sensitivity and invasiveness for patients. In this context, the present study aims to assess, via meta-analysis, the performance of qPCR in diagnosing visceral and cutaneous leishmaniasis.

METHOD

This meta-analysis encompassed studies published between January 2011 and December 2022, sourced from six databases (PubMed, LILACS, Scopus, Scielo, EMBASE, and Web of Science), utilizing the keywords "qPCR," "molecular diagnosis," and "leishmaniasis." Epidemiological studies focusing on the efficacy of qPCR for leishmaniasis diagnosis were included. Data such as study demographics, geographic locations, sampling techniques, and the number of positive qPCR results were aggregated and analyzed to derive overall positivity rates, sensitivity, and specificity values associated with qPCR. Heterogeneity analysis was conducted on the data to select appropriate models, and the collective efficacy data of qPCR were illustrated in forest plots.

RESULTS

Fifty-four studies met all inclusion criteria. The positivity rates for human visceral and cutaneous leishmaniasis were 27.07% (95% CI: 17.81-36.33%) and 60.40% (95% CI: 30.23-90.57%), respectively. In cases of visceral leishmaniasis in dogs, cats, and wild animals, the positivity rates were 26.55% (95% CI: 21.40-31.70%), 0.92% (95% CI: 0.09-1.75%), and 28.98% (95% CI: 21.86-35.10%), respectively. Analysis of the selected studies revealed high overall sensitivity and specificity values achieved with qPCR, at 91.08% (95% CI: 81.77-100.39%) and 98.08% (95% CI: 97.13-99.03%), respectively.

CONCLUSION

This study indicates that qPCR is a highly sensitive and specific tool, adequately suitable for the diagnosis of human visceral and cutaneous leishmaniasis, as well as visceral leishmaniasis in animals.

Seroprevalence and Potential Risk Factors of Toxocariasis among General Population in Southwest Iran: Implications on the One Health Approach

Toxocariasis is one of the most common zoonotic diseases distributed worldwide. This study aimed to estimate the seroprevalence of anti-Toxocara immunoglobulin G (IgG) antibodies and the associated risk factors among general populations living in urban and rural areas of Abadan and Khorramshahr cities in Khuzestan Province, Southwest Iran. This cross-sectional study was conducted between March and September 2022. There were 363 participants (190 females and 173 males) aged from <20 to ≥60 years old. Anti-Toxocara IgG antibodies in serum samples were measured using a commercially available enzyme-linked immunosorbent assay (ELISA). A structured questionnaire was employed to collect information regarding sociodemographic status and probable risk factors associated with toxocariasis. It was found that the seroprevalence rate in males (15.0%, 95% CI = 10.47-21.11) was higher than in females (10.5%, 95% CI = 6.92-15.70). Moreover, we observed that the seroprevalence was higher in participants at younger ages compared to other age ranges (COR = 2.55, 95% CI = 0.92-7.12, p =0.073). The findings of the univariate analysis revealed that residency in rural areas (p  < 0.001), using unpurified water (p  < 0.001), contact with dog (p =0.002), contact with soil (p  < 0.001), consumption of improperly washed vegetables (p  < 0.001), and history of drinking untreated water (p  < 0.001) were risk factors associated with toxocariasis. Further comprehensive studies with a focus on humans and animals should be designed in different areas of the Province. The data represented by the current study are useful to health policymakers to consider precise surveillance and effective prevention measures to control this zoonotic infection among general populations.

Cutaneous Leishmaniasis: Associated Risk Factors and Prevention in Hubuna, Najran, Saudi Arabia

Background

Many countries are currently affected by leishmaniasis, and cutaneous leishmaniasis is ranked among the ten most neglected diseases. The aim of this study was to determine the risk factors related to cutaneous leishmaniasis and preventive measures among people living in Hubuna, Najran, Saudi Arabia.

Methods

A community-based cross-sectional survey was conducted from January to October 2022. A convenience sampling technique was used, with 396 individuals invited to participate in the current study and 391 included. A self-administered questionnaire was utilized for collecting data. Descriptive analysis was used for risk factors and preventive measures, while χ² tests were used for determining associations with risk factors.

Results

Among participants, 38.1% (n=149) reported having cutaneous leishmaniasis clinically diagnosed and under treatment. Age 0-10 years was found to be associated significantly with cutaneous leishmaniasis infection (AOR 3.08, 95% CI 1.6-6.4; P=0.002) compared to other groups. A significant association was noted too for those residing in/around planted areas versus those who were not (AOR 1.18, 95% CI 0.13-2.24; P<0.001). In terms of occupation, farming was significantly associated with cutaneous leishmaniasis (AOR 2.54, 95% CI 1.15-3.76; P=0.010). No significant associations were observed in regard to sex (AOR 1.4, 95% CI 0.7-1.6; P=0.11), education (P=0.072), or preventive measures used (P>0.05).

Conclusion

The cutaneous leishmaniasis endemicity level in Hubuna was high. Several socioeconomic and environmental factors contribute enormously to the spread of the disease in the area. Further investigation of risk factors of cutaneous leishmaniasis all over the country and setting up appropriate interventions to prevent its spread are recommended.

Cutaneous Leishmaniasis Based on Climate Regions in Iran (1998-2021): A Systematic Review and Meta-Analysis

BACKGROUND

Climate change can facilitate the expansion of leishmaniasis and create the suitable habitat for vector and reservoir species. The objective of this study was to estimate the prevalence of cutaneous leishmaniasis (CL) at the climatic regions of Iran.

MATERIALS AND METHODS

The literature search was conducted to identify all published studies reporting the prevalence or incidence of CL in humans in Iran. A total of 350 articles that reported leishmaniasis in Iran were retrieved, due to eligibility criteria, only 42 studies were selected to the final systematic review and meta-analysis procedure. Random effects meta-analysis was done with the estimate of heterogeneity being taken from an inverse-variance model. Subgroup analysis was conducted and it stratified the studies according to climatic regions. Between-study heterogeneity was assessed by using I 2 and Cochran's Q method I 2 value of heterogeneity. Meta regression was used to investigate factors potentially contributed the between-study heterogeneity.

RESULTS

Individual studies showed that prevalence per 100,000 population estimated the range from 1.5 to 318.7 with the overall random pooled prevalence of 83.3 (95% confidence interval 74.5-92.1). Subgroup analysis by climatic regions showed that many studies were conducted in the desert areas and also, it has more prevalent than the other climatic regions.

CONCLUSIONS

Leishmaniasis was more prevalent in regions with dry and desert climates than the other climatic regions. One of the advantages of this work is that the majority of selected studies have been conducted on population-base. However, some of the studies have been designed poorly or have had a lack of internal validity.

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.

Community Engagement in Cutaneous Leishmaniasis Research in Brazil, Ethiopia, and Sri Lanka: A Decolonial Approach for Global Health

Cutaneous leishmaniasis (CL) is a parasitic skin disease endemic in at least 88 countries where it presents an urgent, albeit often “neglected” public health problem. In this paper, we discuss our model of decolonial community engagement in the ECLIPSE global health research program, which aims to improve physical and mental health outcomes for people with CL. The ECLIPSE program has four interlinked phases and underpinning each of these phases is sustained and robust community engagement and involvement that guides and informs all activities in ECLIPSE. Our decolonial approach implies that the model for community engagement will be different in Brazil, Ethiopia and Sri Lanka. Indeed, we adopt a critical anthropological approach to engaging with community members and it is precisely this approach we evaluate in this paper. The data and material we draw on were collected through qualitative research methods during community engagement activities. We established 13 Community Advisory Groups (CAGs): in Brazil (n = 4), Ethiopia (n = 6), and Sri Lanka (n = 3). We identified four overarching themes during a thematic analysis of the data set: (1) Establishing community advisory groups, (2) CAG membership and community representation, (3) Culturally appropriate and context-bespoke engagement, and (4) Relationships between researchers and community members. During our first period of ECLIPSE community engagement, we have debunked myths (for instance about communities being “disempowered”), critiqued our own practices (changing approaches in bringing together CAG members) and celebrated successes (notably fruitful online engagement during a challenging COVID-19 pandemic context). Our evaluation revealed a gap between the exemplary community engagement frameworks available in the literature and the messy, everyday reality of working in communities. In the ECLIPSE program, we have translated ideal(istic) principles espoused by such community engagement guidance into the practical realities of “doing engagement” in low-resourced communities. Our community engagement was underpinned by such ideal principles, but adapted to local sociocultural contexts, working within certain funding and regulatory constraints imposed on researchers. We conclude with a set of lessons learned and recommendations for the conduct of decolonial community engagement in global health research.

Epidemiological features of cutaneous leishmaniasis in diagnosed patients from an endemic area (central Morocco)

Cutaneous leishmaniasis represents the most neglected tropical disease across the world. In Morocco, this disease is endemic and constitutes a major public health problem, with a national control program been implemented. The current study aimed to determine the pattern and epidemiological features of cutaneous leishmaniasis in affected patients in an area covered by the CL control and prevention program (Central Morocco). A total of 161 patients suspected for cutaneous leishmaniasis were diagnosed according to WHO laboratory methods, and 82 cases were confirmed positive for CL. The reports were analysed by patients' socio-geographic status, gender and age. The number and distribution of CL lesions by location, gender and age were investigated. Overall the confirmed cases, 89 % were infected by Leishmania tropica versus 21 % for Leishmania major. Females were significantly more affected than males (p < 0.01). Children (0-15 years), especially those ≤ 7 years of age, were the most affected. For the distribution of lesions, single lesion cases were largely preponderant (70.7 %) compared to multiple lesions. Face location was significantly more frequent (62.2 %) compared to limbs (26.8 %). Face lesions were found more prevalent in children than in adults while limb lesions were highly observed in adults. The pattern of the disease is affected by many factors (e.g. environment, gender, age, etc.) and has specifics to be considered in prevention and control programs in endemic areas.

Low Serum Levels of Selenium, Zinc, Iron, and Zinc/Copper Ratio in an Endemic Region of Cutaneous Leishmaniasis in Southwest Iran

Leishmaniasis is a widespread tropical infection; cutaneous leishmaniasis (CL) is the most common form of this disease known to cause significant morbidity. Trace metals, including selenium, zinc, iron, and copper, are required for the activity of several enzymes involved in immune system responses. The aim of this research was to measure the serum levels of selenium (Se), zinc (Zn), copper (Cu), iron (Fe), and Zn/Cu ratio in patients with CL. In this case-control study, 80 patients with CL and 80 healthy volunteers (not exposed to CL) from a CL endemic region in southwest Iran agreed to participate. Both clinical and parasitological verifications were made to include each subject as a CL-positive case. A questionnaire was completed for each participant which included the following criteria: age (year), height (cm), weight (kg), body mass index (kg/m²), and duration of disease (day). The biochemical assays were performed according to the standard protocols, and the values of Zn, Cu, Se, and Fe were expressed in micrograms per deciliter (μg/dl). All results were expressed as mean ± standard deviation (SD), and the statistical significance level was defined to be less than 0.05 (P < 0.05). There were no statistically significant differences in terms of mean values of age, body weight, height, and body mass index between CL patients and the control group (P > 0.05). The mean ± SD concentrations of Zn, Fe, and Se in the control group were found to be 118.87 ± 6.35 μg/dl, 123.00 ± 8.40 μg/dl, and 11.26 ± 1.88 μg/dl, respectively. These trace elements (TEs) were statistically lower (P < 0.001) in patients with CL (case group) with values of 83.05 ± 7.32 μg/dl for Zn, 86.51 ± 10.09 μg/dl for Fe, and 3.83 ± 1.20 μg/dl for Se. We have also observed that serum levels of Cu in CL-positive group were significantly higher than in the controls (P < 0.001). Furthermore, CL patients had significantly lower Zn/Cu ratio than controls (0.63 ± 0.05 μg/dl vs. 1.11 ± 0.10; P < 0.001). The alternation in serum levels of TEs may be a part of the defense strategy of the organism. Based on these results, it can be suggested that serum levels of these TEs can be a useful marker to estimate the prognosis of CL infection.

Identification of Leishmania species by high-resolution melting analysis in newly emerged foci in Sabzevar, northeast of Iran

Cutaneous leishmaniasis (CL) is a zoonotic disease with 1 to 1.5 million annual incidences. Microscopic examination of the Giemsa stained slides is the most common diagnostic method for CL. However, this method cannot distinguish leishmania species. Hence the present study was conducted to identify leishmania species by high-resolution melting (HRM) analysis in the newly emerged foci of CL in Sabzevar, northeast of Iran. In this cross-sectional study, fifty patients with suspicious cutaneous lesions referring to the designated health center for diagnosis and treatment of CL in Sabzevar during 2017-2018, were recruited. All collected samples and prepared slides were stained for microscopic examination and then undergone HRM real-time PCR (HRM-PCR) assay to identify species of Leishmania parasites. The results of HRM-PCR technique showed that Leishmania major (L. major) was the dominant causative parasite in the newly emerged foci whereas L. tropica (L. tropica) was positive only in two patients. This was the first time that 7SL RNA-HRM-PCR assay was performed to precisely identify leishmania parasites in the northeast of Iran. We proved the newfound foci in which both L. major and L. tropica were present. In contrast to the recent studies which identified only L. major in the region, we showed that L. tropica was still present.

Typical features of cutaneous leishmaniasis in the Ilam province, Iran

Since Cutaneous leishmaniasis is a problematic parasitic infection in the west of Iran, this study was carried out to clarify the epidemiological aspects of Cl. Our database includes all Cl cases with detailed information during 2014-2018 in Ilam province, west of Iran. Patients referred to health and clinical centers in our study areas then health providers and laboratory technicians took smears to detect leishmania parasites under light microscope. SPSS24 software used for analyzing data by the Chi square test. Mehran and Dehloran districts were alone accounted for 50% of all reported cases. ≥ 36 age group was dominant cases also housekeepers were at the top of categories in case of occupation. Hand and leg entangled with this infection more than other organs. Moreover, most cases observed in the winter season, and lesions were 1-3 cm in size. Apart from decreasing Cl cases in our study location compared to 2014, building debris around the urban area should be cleaned up concerning standards of hygiene in each phase to keep rodents away. Additionally, citizens at the land border of Iran-Iraq should protect themselves from sand fly biting at least by insect repellent at peak travel times.