Echinococcus granulosus genotypes in Iran: a systematic review

Phylogenetic Study of cox1 Gene in Echinococcus granulosus Sensu Lato Genotypes in Southwestern Iran

INTRODUCTION

Cystic echinococcosis (CE) is a serious global health concern. CE is an endemic zoonotic disease in Iran. The substantial genetic diversity of Echinococcus granulosus is closely linked to its life cycle, transmission mechanisms and pathogenesis. This study aimed to explore the phylogenetic structure of the genotypes of E. granulosus sensu lato (s.l.) in southwestern Iran (SWI).

METHODS

Seventy-two hydatid cyst samples were collected from various intermediate hosts, including goats, cattle, sheep, camels, buffalo and humans, primarily from the lungs, liver, spleen and heart of livestock slaughtered in local and industrial abattoirs, as well as from patients in several hospitals (Namazi, Golestan, Arvand and Shahid Beheshti) in southwestern Iran (Bushehr, Fars, Kohgiluyeh and Boyerahmad and Khuzestan provinces).

RESULTS

Sequence analysis revealed three genotypes of E. granulosus s.l. in the SWI: G1 (n = 69, 95.8%), G3(n = 1, 1.4%) and genotype like G6/G7 (n = 2, 2.8%). Twenty-one different haplotypes were identified in this study. According to the phylogenetic tree topology, the cox1 gene sequence similarities can be shown for some G1 and G6/G7 isolates in some vast areas, but these genotypes generally show a heterogeneous population worldwide. High similarity was shown between G3 isolates from some countries (Spain, Turkey, India and Iran) and different hosts (sheep, human and buffalo).

CONCLUSIONS

The presence of the G6/G7 genotype in the SWI may be due to the transmission of this genotype from other regions or the role of camel/wild boar and other possible intermediate hosts in the expansion of this genotype in the SWI. The results of the present study can be used in CE control programs, molecular epidemiology and phylogenetic studies in Iran and other countries for future goals.

A ten-year evaluation of central nervous system cystic echinococcosis in a highly endemic area of Iran: Molecular epidemiology and clinicopathological characteristics

Cystic echinococcosis can involve various organs in humans with the brain and spine being particularly vulnerable. This research aimed to study clinicopathological features and molecular analysis of the central nervous system (CNS) echinococcosis cases in a central hospital for hydatid cyst surgery in northeastern Iran. CNS echinococcosis cases from surgically managed human CE cases at Ghaem hospital in northeastern Iran were analyzed from 2012 to 2022. Demographic and clinicopathological data were collected for CNS echinococcosis cases and formalin-fixed paraffin-embedded (FFPE) blocks were used for molecular analysis. The total prevalence of CNS echinococcosis cases was 1. 8 %. Most of the CE cases were reported in women (64. 7 %) and from rural areas (58. 8 %). The highest number of cases (41. 2 %) were aged ≤18 years, with majority being ranchers (47. 1 %). Thirteen cases (76.5 %) were found to have cysts in their brain, particularly in the supratentorial site. Headache was the most commonly reported sign in cases (9/13, 69.2 %). Infiltration of eosinophils, polymorphic inflammatory cells, and giant cells, gliosis, and foreign body granulomatous reaction, along with mild infiltration of mononuclear cells showing degeneration and necrotic foci in the brain infections. Spine infections included bone cartilage, ligaments, and hydatid cyst wall fragments. PCR analysis conducted on 17 samples revealed the presence of 13 isolates of E. granulosus sensu lato. Among these, 11 were classified within the E. granulosus sensu stricto (G1 and/or G3) complex, while 2 isolates were identified as belonging to the E. canadensis G6/G7. Cerebrospinal infection is a significant aspect of CE cases in northcentral Iran, with a higher prevalence among women and in rural areas. Children were the most affected age group, with the E. granulosus s.s. genotypes being the most common.

Global distribution and definitive host range of Echinococcus species and genotypes: A systematic review

Echinococcus species (spp.) are regarded as neglected cestodes causing several potential zoonoses of global public health. This systematic review critically appraises the worldwide distribution of Echinococcus spp. and genotypes (Echinococcus spp.: recognized species in the genus; genotypes: variants identified within E. granulosus sensu lato.) in definitive hosts. We analyzed 82 studies from major databases, comprising 24 individual host species, including canids, felids, and a hyenid species. Canids, particularly dogs, were the most studied group among the host species, with E. granulosus sensu stricto (G1-G3) being the most frequently reported. E. granulosus s.s. was distributed across five major continents, while other Echinococcus spp. and genotypes exhibited an uneven continental distribution. The highest overlap of species existed among Asia, Europe, and Africa. Among the reported host species, 4.2 % were endangered (e.g. Lycaon pictus), 12.5 % species were vulnerable (e.g. Panthera leo, Panthera pardus, and Acinonyx jubatus), and 4.2 % were near threatened (e.g. Speothos venaticus). Overall, our review highlights the significance of canids, particularly dogs, as the core focus of scientific investigations, with E. granulosus s.s. being the most widely distributed species across five major continents, emphasizing the urgent need for continued research and public health efforts.

Morphometrical and molecular identification of Echinococcus granulosus genotypes in wild canids in north of Iran

BACKGROUND/OBJECTIVE

The cestode Echinococcus granulosus causes cystic echinococcosis, a zoonotic parasitic infection that constitutes a significant public health risk. This parasite has been documented to have potential reservoirs and carriers among wild canids, namely wolves, foxes and jackals. This study aimed to determine the prevalence and molecular characteristics of E. granulosus sensu lato species/genotypes among wild canids in three northern, northeastern and north-western Iran regions.

METHODS

From 2019 to 2022, 93 wild canid carcasses (69 jackals), (22 foxes) and (2 wolves) were collected that were killed in car accidents or illnesses. Analyses of morphology and morphometry were performed to verify the presence of E. granulosus. To determine E. granulosus s.l. species/genotypes, polymerase chain reaction (PCR)-RFLP (ITS1) was performed utilizing the Bsh1236I (BstUI) restriction enzyme. COX1, NADH1 and ITS1 gene sequencing were also performed to confirm the PCR-RFLP results.

RESULTS

During this study, 93 wild canids were examined, and 3.2% (95% CI: 0%-7%) of the 93 were infected with Echinococcus. The north-western region of Iran showed two out of 30 jackals (6.6%) infected with adult Echinococcus compared to one out of 35 jackals (2.8%) in the northern region. DNA from Echinococcus was detected in these individuals by PCR. Based on PCR-RFLP analysis of the ITS1 gene and sequencing of COX1, NADH1 and ITS1 gene, E. granulosus sensu stricto genotype was confirmed in the jackals that had been infected.

CONCLUSION

Evidence shows that E. granulosus occurs in jackals in Iran, with the E. granulosus s.s. genotype being the most common. This parasite has been identified as a zoonotic parasite with a genotype that can be transmitted to livestock and humans. Establishing effective control measures to prevent the spread of echinococcosis and ensure public health is crucial.

Environmental contamination with feces of free-roaming dogs and the risk of transmission of Echinococcus and Taenia species in urban regions of southeastern Iran

BACKGROUND

Dogs are the most important definitive hosts of zoonotic taeniid helminths worldwide. Different Echinococcus and Taenia species of domestic and wild carnivores pose a potential risk to human population. High populations of free-roaming dogs (FRDs) in urban areas of Iran and widespread contamination of the environment with dog feces is a potential source of infecting people living in the urban regions with cystic echinococcosis (CE). Our knowledge on the risk of CE transmission in the urban settings in the endemic regions is limited. The present study surveyed the species and genotypes of E. granulosus sensu lato and other taeniids by examining feces of free-roaming dogs in the urban areas in the city of Kerman, southeastern Iran.

METHODS

The city was divided into 100 consecutive blocks of which 25 blocks were randomly selected. Fecal samples of FRDs were counted, mapped and fresh samples were collected. Then Zinc chloride flotation, and sequential sieving was performed, and the samples were examined under an inverted microscope. Single individual taeniid eggs were isolated, partial nad1 gene was amplified and sequenced to identify species and genotypes.

RESULTS

In total 5607 fecal samples of dogs were mapped and 83 fresh samples were collected. Taeniid eggs were detected in nine fecal samples (10.8%) from seven out of the 25 city blocks (28.0%). Echinococcus eggs were found in four samples (4.8%) from three city blocks, two samples containing E. granulosus sensu stricto (2.4%), two samples containing E. canadensis G6/7 (2.4%). In addition, three samples contained eggs of Taenia hydatigena (3.6%), and one sample of Taenia serialis (1.2%).

CONCLUSIONS

This study documented the potential risk of CE transmission to humans resulting from the feces of dogs roaming freely in urban areas.

Seroprevalence and risk factors associated with toxoplasmosis and hydatidosis among the butchers of Tabriz city, the northwest of Iran: a case control study

INTRODUCTION

Occupation plays an important role in the spread of infectious diseases in humans. Toxoplasmosis and hydatidosis are world-wide diseases with different routes of transmission. This study aimed to investigate the prevalence of toxoplasmosis and hydatidosis and risk factors associated with these diseases among the butchers of Tabriz City, the northwest of Iran.

METHODS

In this case-control study conducted in Tabriz city in 2023, 250 serum samples were collected from butchers (n = 125) and outpatients referred to Imam Reza Hospital (n = 125) and. The ELISA test was used to identify IgG and IgM antibodies against toxoplasmosis and IgG antibodies against hydatidosis. The results were analyzed by statistics tests using SPSS v. 16 software. Risk factors' association was tested using Chi square or logistic regression analysis.

RESULTS

The results indicated that 66/125 (52.8%) cases and 40/125 controls (32%) were positive for toxoplasmosis IgG antibody. Also, 5/125 (4%) and 1/125 (0.8%) were positive for toxoplasmosis IgM antibody in the case and control groups, respectively. In addition, 10/125 people (8%) were positive for anti-hydatidosis IgG antibody in the case group, while no positive cases were found in the control group. The main risk factors for toxoplasmosis were age (OR: 1.014), education level (OR: 0.638), and work experience(OR: 1.695), these factors for hydatidosis included age and education level (OR: 1.765 and 0.271) respectivily.

CONCLUSIONS

Our results suggest the high prevalence of toxoplasmosis and in butchers of Tabriz, which required special attention and basic measures. Moreover, the prevalence of hydatidosis IgG antibodies also requires more attention to be focused on breaking the transmission and reducing the infection.

Molecular characterization of cystic echinococcosis cysts isolated from cattle in Shiraz, Iran

Cystic echinococcosis (CE), is one of the common parasitic infections of domestic animals and humans caused by the larval stages of the tapeworm Echinococcus granulosus. This research aimed to identify of CE cysts in cattle isolates from Shiraz slaughterhouse using molecular technique. Thirty CE cysts isolates were collected and total DNA was extracted from protoscolices or the germinal layer of each cyst followed by polymerase chain reaction (PCR) using cytochrome c oxidase I (cox1) and NADH dehydrogenase subunit 1 (NADH-1) mitochondrial genes (~ 450 bp) and sequencing. The sequence results were compared with available reference sequences in GenBank by BLAST system. Phylogenetic analysis was performed using MEGA 5.0 software and the maximum likelihood method. The results showed that all 30 samples examined in this study were identified as E. granulosus sensu stricto (G1-G3 genotypes) with G1 dominant.

Identification and genotyping of Echinococcus granulosus from human clinical samples in Guilan province, north of Iran

Cystic echinococcosis (CE) is a significant health problem in both human and veterinary medicine. It is caused by the tapeworm Echinococcus granulosus (E. granulosus). The objective of this study was to investigate molecular diversity of E. granulosus from the paraffin-embedded human (FFPE) tissue samples using sequencing of mitochondrial genes. Thirty-five FFPE tissue samples were collected from different regions of Guilan province, north of Iran. Demographic data were recorded using a questionnaire. Five sections (1 mm) of the tissue were prepared and deparaffined using xylene and ethanol methods. Molecular analysis was performed using the Nad1 and Cox1 genes using PCR and DNA sequencing. Totally, 25 cases (71.43%) were women and 10 cases (28.57%) were men. The most affected age group was 21-30 yr old. The most of cysts were isolated from the liver (n = 19; 54.29%) and others in the lung (n = 16; 45.71%). The Cox1 and Nad1 genes were successfully amplified in 16 (45.71%) and 12 (34.28%) DNA samples from FFPE tissue. Sequencing analysis revealed that all samples were E. granulosus sensu stricto complex (G1 and G3). In this study, E. granulosus sensu stricto complex G1 and G3 were identified in human hydatid cysts and showed the presence of sheep/dog cycle in human infection. This finding confirmed and completed previous studies on the geospatial distribution of E. granulosus sensu stricto complex G1 and G3 in the southern and coastal areas of the Caspian Sea region.

Detection of circulatory E. granulosus-derived cell-free DNA in the plasma and urine of human cystic echinococcosis using an in-house PCR: a potential promising diagnostic biomarker

BACKGROUND

The diagnostic tool for identifying cystic echinococcosis (CE) patients at an early stage is currently lacking. However, circulatory cell-free DNA (cfDNA) has shown potential as a biomarker for parasitic infections and could be used for diagnosing CE.

RESEARCH DESIGN AND METHODS

The plasma and urine samples were collected from 39 patients with confirmed CE through imaging and histopathological techniques. All plasma samples were tested for anti-echinococcal antibodies using a commercial ELISA test. Total plasma and urine cfDNA were extracted and an in-house PCR assay was developed to detect E. granulosus specific cfDNA in the samples of CE patients.

RESULTS

Out of the 39 patients, 30 tested positive for E. granulosus using serology, with a sensitivity of 76.9%. Moreover, the detection rates for the cfDNA were 79.5% in plasma samples and 58.97% in urine samples using the 80 bp COX1 gene. The plasma-based PCR and serology test showed the highest agreement (Kappa = 0.53).

CONCLUSIONS

Plasma-based PCR has been found to be a reliable diagnostic tool for identifying CE patients at different cyst stages. It offers validity, speed, and sufficient sensitivity, making it an alternative to serology in diagnosing CE in endemic areas.

Echinococcus granulosus sheep strain (G1) as the predominant genotype in definitive host (dogs) isolates in northeastern Iran

Echinococcus granulosus sensu lato (E. granulosus s.l.) is a zoonotic parasite, causing cystic echinococcosis in humans. In the present study, prevalence and genotypes of E. granulosus s.l. was assessed in stools collected from 244 dogs including 138 stray and 106 domestic animals using high resolution melting curve (HRM) method. Initially, to detect taeniid eggs in feces, all samples were examined using the formalin-ether techniques. Genomic DNA was extracted from the positive samples and E. granulosus s.l. was differentiated from other Taeniidae parasites using SSU-rDNA gene and E. granulosus s.l. was analyzed for genotyping using HRM based on the cox1 gene. In total, 12.7% (31/244) of the samples were positive for Taeniidae eggs. In addition, among the positive samples, 77.4% (24/31) were positive for E. granulosus s.l.. In details, 11.3% (12/106) of the domestic dogs and 8.7% (12/138) of the stray dogs were positive for E. granulosus s.l.. The results of HRM analysis showed that all E. granulosus s.l. isolates were G1 strain. Findings of the present study indicated a considerable prevalence of E. granulosus G1 among dogs in the northeast of Iran and imply a serious risk of transmitting to humans and livestock.

Genotyping of Echinococcus granulosus isolated from canine in Northwest Iran

Echinococcus granulosus is a parasitic tapeworm that causes cystic echinococcosis, a potentially life-threatening zoonotic infection affecting humans and animals across the globe. In Iran, the prevalence of this parasite remains a significant public health concern, particularly in the northwest region. This study aimed to investigate the genotypes of E. granulosus isolated from canines in the northwest of Iran. A total of 87 samples were collected from the Mughan plain area in Ardabil province, including 47 stray dogs (Canis familiaris), 25 golden jackals (Canis aureus), and 15 red foxes (Vulpes vulpes), and molecular analysis was performed for partial cytochrome c oxidase subunit 1 and nad1 genes. Phylogenetic analyses were carried out on the obtained sequence. The findings revealed that 9 out of 87 (10.3%) samples were infected with Echinococcus parasites, with a frequency of 1 (4%) and 8 (17%) among golden jackals and stray dogs, respectively. Overall, all (100%) E. granulosus adult samples were related to the G1 genotypes. This study provides comprehensive data regarding the epidemiological and molecular characteristics of echinococcosis in canines in northwest Iran.

In vitro and in silico scolicidal effect of sanguinarine on the hydatid cyst protoscoleces

We aimed to investigate the scolicidal effects of sanguinarine on hydatid cyst protoscoleces (PSCs) in vitro and in silico. Different targets were docked into the active sites of sanguinarine. Molecular docking processes and visualization of interactions were performed using AutoDock Vina and Discovery Studio Visualizer. Binding energy was calculated and compared (kcal/mol). PSCs were aspirated from the hydatid cysts and washed. The sediments of PSCs were then exposed to various concentrations (50, 25, 12, 6, 3, and 1 μg/mL) of sanguinarine. The viability test was finally evaluated by the Trypan blue solution 4%. Levels of malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPX), and catalase were analyzed to assess the level of oxidative stress-treated PSCs. Caspase-3 activity rate was determined to evaluate cell apoptosis in treated PSCs. Among the receptors, acetylcholinesterase was identified as the excellent target, with Vina score of -11.8. Sanguinarine showed high scolicidal effects after 12, 24, and 48 h. Also, in the first hour of exposure to the drug, caspase-3 activity and MDA level significantly increased, but the levels of GSH and GPx had a significant reduction after 12, 24, and 48 h (P < 0.05). The findings of this study revealed that sanguinarine have potent scolicidal effects in vitro and in silico and could be considered an opportunity for the introduction of a novel and safe therapeutic agent for the treatment of cystic echinococcosis. However, supplementary studies will be desired to prove the current findings by examining sanguinarine in a clinical setting.

Application and evaluation of native antigen B from Echinococcus granulosus sensu stricto and E. canadensis alone or mixture for serodiagnosis of human G1-G3 and G6/G7 genotypes cystic echinococcosis sera, using ELISA and Western blotting

Cystic echinococcosis (CE) is one of the most important helminthic diseases in the world with different genotypes distribution. The application of specific genotype antigens together with sera from patients with specific cyst genotypes have not been reported, so far. The present study aimed to apply and evaluate native AgB from Echinococcus granulosus sensu stricto (Eg) and Echinococcus canadensis (Ec) alone or mixture for serodiagnosis of human G1-G3 and G6/G7 genotypes cystic echinococcosis sera, using ELISA and Western blotting. A total of 47 human sera along with 47 human CE cysts were collected. CE genotypes were determined. Native AgB were prepared from E. granulosus s.s and E. canadensis genotypes. ELISA and Western blot were performed on human specific G1-G3 and G6/G7 genotypes sera. Species specific native AgB were used alone or mixed. The sensitivity of ELISA using alone and mixed 1Eg-1Ec, 1Eg-2Ec, and 2Eg-1Ec of native AgB from E. granulosus s.s and E. canadensis genotypes for human G1-G3 sera were 92.10, 89.47, 97.37, 100, and 100%, respectively; while using AgBs, alone and mixed for human G6/G7 sera were 100%. The sensitivity of Western blotting using native AgB of E. granulosus s.s and E. canadensis genotypes alone and mixed 2Eg-1Ec were 78.95% and 100% for human G1-G3 and G6/G7 genotypes sera, respectively. The mixture of AgB from Echinoccus granulosus sensu stricto and Echinococcus canadensis genotypes increased ELISA sensitivity for the diagnosis of human CE. Preparation and application of native AgB from specific and prevalent genotypes of CE in endemic regions is recommended.

Status of human cystic echinococcosis based on hospital records in Mazandaran Province: A first registry-based evidence

Background

Human cystic echinococcosis, as an emerging neglected parasitic disease, is caused by tapeworms of the genus Echinococcus spp. Because of the medical and economic importance, this study aims to review the epidemiology and clinical features of hydatidosis in patients admitted to medical and surgical wards in three referral teaching hospitals over 15 years in Mazandaran Province, northern Iran.

Methods

Data were collected from hospital records that were accessible via the hospital information system (HIS) between 2005 and 2019 (15 years).The demographic information (age, sex, living area, and occupation), dog contact, number of the cysts, types of organs involved, and history of disease recurrence were assessed.

Results

One hundred twenty-one patients with human cystic echinococcosis (CE) were involved in the study, from whom 58 patients (47.93%) were male and 63 (52.07%) were female. The majority of patients were rural residents (64.46%) and also housewife (28.10%). Based on the results, only about 16.53% of the patients had history of close contacts with dogs. The liver was the organ involved in the most cases of CE. There were statistically significant differences between residence, occupation, history of close contacts with dogs, type of organs involved, number of cysts and history of disease recurrence (P < 0.05).

Conclusions

Our data provides valuable registry-based information about CE in an endemic region. The data highlights that most patients lived in rural areas and were housewives. Additionally, they had a low rate of disease recurrence but a high rate of close contact with dogs. Moreover, further monitoring on registry-based program and strengthening the HIS in the provincial hospitals in the studied area are required.

Anti-Tumor Effect of Protoscolex Hydatid Cyst Somatic Antigen on Inhibition Cell Growth of K562

BACKGROUND AND OBJECTIVE

Today, cancer is one of the most important causes of death in the world, and so far, many treatment methods have been used in this field. Immunotherapy is considered one of the newest developments in this science, and it is still being investigated in some forms in different cancers and with a variety of antigens as well. One of the subsets of cancer immunotherapy is its treatment using parasitic antigens. The present study evaluated the effect of using somatic antigens of protoscoleces of Echinococcus granulosus on K562 cancer cells.

METHODS

In this study, hydatid cysts' protoscolex antigens were extracted, purified, and added to K562 cancer cells at three concentrations (0.1, 1, and 2 mg/ml) and on three times (24, 48, and 72 h). The number of apoptotic cells was compared to the control flask. The antigen concentration of 2 mg/ml was used as a control sample to investigate its cytotoxic effect on the growth of healthy HFF3 cells. Annexin V and PI tests were also performed to differentiate apoptosis from necrosis.

RESULTS

In flasks treated with hydatid cyst protoscolex antigen, all three concentrations significantly reduced the growth of cancer cells compared with the control flask, and concentration 2 of crude antigen significantly caused the death of cancer cells. Furthermore, more cancer cells underwent apoptosis by increasing the time of exposure to the antigen. On the other hand, flow cytometry results also showed that the amount of apoptosis has increased compared to the control group. In fact, Protoscolex hydatid cyst somatic antigens induce programmed cell death in K562 cancer cells while not having a cytotoxic effect on normal cells.

CONCLUSION

Therefore, it is suggested to do more research on the anti-cancer and therapeutic properties of the antigens of this parasite.

The occurrence of cystic echinococcosis in slaughtered livestock in Jahrom, south of Iran

Cystic echincoccosis (CE) is a major medical and veterinary concern in the world, especially in Iran. Domestic intermediate hosts are an important reservoir for the disease spread. The purpose of this study was to determine the prevalence of CE in slaughtered livestock in Jahrom, south of Iran. In this cross-sectional study, a total of 3074 animals (2325 (75.63%) goats, 423 (13.76%) sheep, and 326 (10.60%) cattle) were inspected macroscopically for CE. In this regard, a questionnaire about the age, sex, infected organ, number of cysts, and cyst fertility was accomplished for each animal. Moreover, PCR was applied by using the cytochrome c oxidase I (COX1) and NADH dehydrogenase subunit 1 (nad1) fragments of parasite mitochondrial genomes on some positive samples. Prevalence of CE in sheep, cattle, and goats was 11.34% (48/423), 11.04% (36/326), and 2.79% (65/2325), respectively. In all livestock, CE was more common in females than males. Moreover, the highest infection rate was observed in the age group of more than 72 months. Considering the fertility of cysts, the ratio of the number of fertile cysts to total cysts in sheep and goats were 83.3% (40/48) and 80% (52/65), respectively. All hydatid cysts were infertile in cattle. With regard to the location of the cyst on internal organs, the most were observed in the lungs and liver. Regarding the intensity of infection, 1–5, 6–9 and ≥ 10 cysts were detected in 78.52% (117/149), 6.71% (10/149) and 10.73% (16/149) of infected livestock, respectively. In all livestock, hydatid cyst with a diameter of 1–5 cm was the most frequent with 71.81% (107/149). All 149 cyst samples were subjected to PCR. Among them, a total of 18 samples (six samples of each animal) were prepared for sequencing. G6 was the most dominant. According to the results of present study and the relatively high prevalence of CE in slaughtered livestock in Jahrom, health policy makers, health authorities, and experts should make effective approach in this regard, and implement careful inspections.

Global distribution of Echinococcus granulosus genotypes in domestic and wild canids: a systematic review and meta-analysis

The current systematic review and meta-analysis demonstrate the genotypic distribution of canine echinococcosis worldwide. Studies published from the inception until 21 May 2021 were screened, relevant articles were selected and the random-effect model was used to draw forest plots with 95% confidence intervals (CIs). Totally, 44 articles were included, mostly examined dogs (37 records), followed by wolf (8 records), jackal (7 records), fox (3 records), pump fox (3 records) and coyote (1 record). Echinococcus granulosus sensu stricto (G1–G3) and G6/7 cluster of Echinococcus canadensis were the most common genotypes among canids. Most studies were conducted in Asia and Europe with 17 and 15 datasets, respectively. Exclusively, Iran possessed the highest number of studies (10 records). Meta-analysis showed that the pooled molecular prevalence of echinococcosis was 33.82% (95% CI 24.50–43.83%). Also, the highest and lowest prevalence of canine echinococcosis was calculated for South America (66.03%; 95% CI 25.67–95.85%) and Europe (19.01%; 95% CI 9.95–30.16%). Additionally, there were statistically significant differences between the global prevalence of echinococcosis in canines and publication year, continent, country, sample type, host and molecular test. These findings will elevate our knowledge on the poorly known canine echinococcosis worldwide.

Bacterial and Fungal Occurrence in Hydatid Cysts from Livestock in Central Iran

Echinococcus granulosus sensu lato causes Cystic echinococcosis. This study investigated the bacterial and fungal species in the liver and lung hydatid cysts obtained from sheep, goats, cattle, and camels slaughtered in Yazd abattoir, Central Iran. In this study, 84 hydatid cysts were obtained from 20 sheep, 13 goats, 25 cattle, and 26 camels. The fertility and viability rates were assessed using light microscopy and eosin staining, respectively. The aspirated hydatid cysts were cultured to detect the presence of any bacteria and fungi. Bacterial isolates were identified by biochemical tests. DNA was also extracted from germinal layers, and then genotyping was carried out targeting the cox 1 gene. The statistical analysis was performed by SPSS version 16.0. This study showed that 22.62% (19/84) of hydatid cysts had bacterial occurrence, and none of the samples had fungal species. Among the fertile cysts, 52.6% had bacterial occurrence, of which 40% were viable. Most bacteria detected in hydatid cysts included Staphylococcus saprophyticus, Escherichia coli, and S. epidermidis. Hydatid cysts with bacterial occurrence were identified as G1-G3, G5, and G6/G7. The bacterial species occurrence in hydatid cysts had no significant relationship with fertility and viability (P > 0.05), without any significant relation with viability (P > 0.05), animal species (P > 0.05), involved organ in animals (P > 0.05), and hydatid cyst genotypes (P > 0.05). It should also be mentioned that this is the first study to assess the relationship between hydatid cyst genotyping and the occurrence of fungal and bacterial species.

Echinococcus granulosus sensu lato Genotypes in Different Hosts Worldwide: A Systematic Review

INTRODUCTION

The aim of this study was to develop a synthesis of the evidence available regarding verified E. granulosus sensu lato (s.l.) genotypes in different species worldwide.

MATERIAL AND METHODS

A systematic review was performed including studies concerning genotypes of E. granulosus s.l. without language or genotyped method restriction, published between 1990 and 2020. A systematic search was carried out in Trip Database, BIREME, SciELO, LILACS, IBECS, PAHO-WHO, EMBASE, PubMed, Scopus, and WoS. Variables of interest were year of publication, country, number of samples, and hosts; genotypes, molecular marker, haplotypes and molecular biology techniques used. Descriptive statistics were applied.

RESULTS

2411 articles were analyzed, however 135 met the selection criteria, representing 8643 liver and lung samples. Of the samples selected 24% were human, the remaining samples pertained to non-human animal hosts; cattle and sheep prevailed with 28.6% and 26.6% of the studied samples, respectively. The reported evidence is mainly from Iran, Turkey, Argentina, China and Chile; with 50, 11, 6, 6 and 5 studies, respectively, published between 1992 and 2020 [most frequently during 2015-2020 (76/135 studies; 56.3%)]. The mitochondrial gene cox1 was generally sequenced and informative (91.8%). Genotypes most frequently identified were E. granulosus sensu stricto (s.s.) (83.2%).

CONCLUSIONS

Based on this overall evidence, it can be concluded that publications related to genotypes of E. granulosus s.l. are heterogeneous. E. granulosus ss accounts for the vast majority of the global burden of E. granulosus s.l. worldwide. Further studies including larger number of cases and adequate internal validity are required to specify the distribution of genotypes in various host species.

TRIAL REGISTRATION

PROSPERO CRD42018099827.

Multivesicular hepatic human hydatid cyst from Iran: First genotyping-based confirmation

Cystic echinococcosis is one of the most important zoonotic parasitic diseases caused by the tapeworm Echinococcus granulosus. To date, the genotype of multivesicular CE has not been identified. In this regard, the genotyping of multivesicular types of CE could help clinicians understand and manage the disease effectively.

Occurrence and genetic characterization of Echinococcus granulosus sensu lato from domestic animals in Central Iran

Background

The species complex of Echinococcus granulosus sensu lato (s.l.) causes cystic echinococcosis distributed worldwide. There is no genotype information from hydatid cysts in the intermediate hosts in Central Iran. Therefore, in this study, we analyzed the hydatid cysts in livestock slaughtered in an abattoir in this region. Six hundred fifty-seven hydatid cysts were isolated from 97 animals, including sheep, cattle, camels, and goats slaughtered in Yazd abattoir from September 2018 to January 2020. The demographic data was collected as well as cyst location, fertility, and viability. Out of 657 samples, 164 samples were genotyped. Then, phylogenetic analysis was performed using MEGAX. Statistical analyses were done using SPSS version 16.0 by chi-square with a significant difference of less than 0.05.

Results

Out of 164 samples, the G1-G3 complex genotype had the most frequency in samples, with 135 cases recognized. The G6/G7 was observed in 19 isolates and G5 was reported in nine samples. One sample was detected as Taenia hydatigena.

Conclusions

This study showed that G1-G3 and G6/G7 genotypes were presented in all animals, but G5 was reported only in cattle, goats, and camels. It is the first molecular identification of cystic echinococcosis in Central Iran. Hence, reporting G5 in livestock in this area should be considered due to transmission to humans.

Sequence analysis, intra-genotyping variation, and phylogenetic study of nad1 gene in Echinococcus granulosus sensu lato genotypes from intermediate hosts in southwestern Iran

Cystic echinococcosis (CE) is caused by the larval stage of Echinococcus granulosus sensu lato (s. l.). The disease is cosmopolitan, and Iran is a highly endemic area for CE. This parasite exhibits high genetic diversity, which can be related to its life cycle, transmission, and pathogenesis. This study was aimed at determining the phylogenetic relationship and intra-genotyping variation of E. granulosus s.l. in a vast area in the southwest of Iran (SWI). Eighty hydatid cyst isolates of intermediate hosts (i.e., cattle, sheep, goat, buffalo, camel, and human) were collected. The sequence analysis of the nad1 gene exhibited the three genotypes of G1 (n = 70, 87.5%), G3 (n = 8, 10%), and G6/G7 (n = 2, 2.5%). Also, 16, 2, and 1 unique haplotypes were identified for the G1, G3, and G6/G7 genotypes, respectively. According to the phylogenetic tree topology, the nad1 gene similarities were found for some G1 isolates in some vast areas, and the G1 genotype showed a heterogeneous population worldwide. The only SWI G6/G7 haplotype was at a distant position in E. canadensis clade, indicating the notable difference of this haplotype from other isolates from Iran and other countries. The presence of the G6/G7 genotype in the SWI may be due to the transmission of the genotype from other regions or the role of camel/wild boar or other possible hosts in the expansion of this genotype in SWI. The results of the present study can be used in CE control programs, molecular epidemiology, and phylogenetic studies in Iran and other countries for future goals.

Molecular Characterization and Haplotype Analyses of Lung Hydatid Cyst Isolates of Cattle and First Report of Echinococcus canadensis (G6/G7) in Cattle Isolates in Turkey

PURPOSE

Cystic echinococcosis (CE) is a zoonotic disease, caused by parasite known as Echinococcus granulosus sensu lato complex, leading to substantial economic losses in rural areas with public health problems. This study was carried out to understand the haplotypic profiles of the partial mitochondrial cytochrome c oxidase (mt-CO1) gene of cattle lung hydatid cyst samples which were obtained from two provinces in Turkey.

METHODS

In this study, forty (n = 40) hydatid cyst samples from the lungs of slaughtered cattle were obtained. The germinal layers were taken separately for each individual cyst then stored in 70% ethanol. From each individual cyst sample, total genomic DNA was extracted. Amplification of the partial mt-CO1 gene (875 bp) was performed using a specific primer set by PCR, and then, the amplicons were sequenced. All sequences were analyzed individually, followed by alignment, and haplotype and phylogenetic analyses were then performed.

RESULTS

By the sequence alignment process, 39 out of the 40 sequences were characterized as E. granulosus sensu stricto. However, one of them was matched with E. canadensis (G6/G7). The haplotype analyses of the E. granulosus s.s. isolates were arranged in a star-like orientation with a main haplotype, which was separated from other haplotypes by 1-10 mutation steps, and 26 haplotypes were identified. In the mt-CO1 sequences, 29 polymorphic sites were determined, and 34.5% (10/29) of them were parsimony informative.

CONCLUSIONS

The findings of this study provide the first report of E. canadensis (G6/G7 genotype) among cattle in Turkey.

Screening of Cystic Echinococcosis and Toxocariasis in Urmia Municipal Workers, Northwest Iran

BACKGROUND

Echinococcus granulosus and Toxocara spp., the causative agents of hydatid cyst and toxocariasis in humans and animals, are zoonotic infections with medical and veterinary significance respectively.

AIM

Herein, we aimed to investigate the seroprevalence of toxocariasis and cystic echinococcosis in Urmia municipal workers (gardeners and sweepers) in 2018 using ELISA assay.

OBJECTIVE

There is no precise report on the seroprevalence of toxocariasis and cystic echinococcosis in Urmia municipal workers using ELISA assay. Therefore, this study found an opportunity to investigate this subject.

METHODS

A total of 220 blood samples were obtained from municipal workers with an average age of 41.31 ± 9.42. Commercial anti-Toxocara canis and hydatid cyst ELISA kits were used to assess the seroprevalence rates.

RESULTS

Approximately, 14.5% and 2.3% of individuals were seropositive for toxocariasis and hydatidosis, respectively. Consuming unboiled milk and/or raw/uncooked meat and rural conditions are risk factors for toxocariasis. Regarding hydatidosis, consuming unwashed vegetables was the only statistically significant risk factor. Toxocara infection (p = 0.01), but not hydatid cyst (p = 0.05), is more prevalent among sweepers than municipal gardeners.

CONCLUSION

Due to the occupational condition of municipal workers, they are exposed to many infectious agents; thus, more researches should be done on these populations.

Silybum marianum ethanolic extract: in vitro effects on protoscolices of Echinococcus granulosus G1 strain with emphasis on other Iranian medicinal plants

BACKGROUND

Cystic echinococcosis (CE), is a parasitic zoonosis caused by Echinococcus granulosus (E. granulosus) larvae in liver and lungs of both humans and animals. Surgical intervention is the mainstay for CE treatment, using scolicidal agents that inactivate live protoscolices. This study evaluated the scolicidal effects of Silybum marianum ethanolic extract and its combination with albendazole in vitro for the first time. Moreover, in a literature review, we investigated the effects of a wide range of Iranian medicinal plants on protoscolices of E. granulosus.

METHODS

S. marianum ethanolic extract was prepared and high-performance liquid chromatography (HPLC) analysis was used to establish the proportions of its component compounds in the extract. Cytotoxicity was evaluated in mouse macrophage cells (J774A.1 cell line) using MTT method. Next, the scolicidal activity of the extract alone and combined with albendazole was tested as triplicate at various concentrations incubated for 5, 10, 20, 30, and 60 min. Finally, protoscolex viability was determined using 0.1% eosin as a vital stain. PCR-RFLP and DNA sequencing techniques were used to characterize the genotype of E. granulosus.

RESULTS

HPLC analysis showed that S. marianum ethanolic extract contained mostly silydianin (14.41%), isosilybin A (10.50%), and silychristin (10.46%). The greatest scolicidal effects were obtained with the combination of S. marianum with albendazole (79%), S. marianum ethanolic extract alone (77%) and albendazole (69%), at a concentration of 500 μg/ml for 60 min, respectively (P < 0.05). Molecular analysis showed that all the cysts used were G1 genotype.

CONCLUSION

The data suggest that S. marianum ethanolic extract is a potential scolicide in vitro; however, further investigations are required to determine its efficacy in vivo.

Echinococcus granulosus sensu stricto G1 is the predominant genotype in human and livestock isolates from Turkey and Iran, based on mitochondrial nad5 gene differentiation

BACKGROUND

Different genotypes of Echinococcus granulosus sensu stricto (s.s.) isolated from livestock and humans have been identified based on cox1 and nad1 genomic fragments. The present study was performed to differentiate the G1/G3 genotypes of Echinococcus granulosus (s.s.) isolated from humans and livestock (sheep and cattle) from Azerbaijan in northwestern Iran, Fars Province in southern Iran, and Van province in Eastern Turkey, using the nad5 gene fragment as a suitable marker to distinguish these two genotypes.

METHODS

A total of 60 pathologically confirmed human hydatid cysts and 90 hydatid cyst samples from livestock were collected from Turkey and Iran. PCR was performed on all of the samples, targeting the nad5 gene. Based on PCR product quality, host type, and the geographical area where the samples were obtained, 36 of the samples were sequenced and were used in the phylogenetic analysis.

RESULTS

Out of 36 evaluated samples, 26 (72.2%) samples belonged to G1, and 10 (27.8%) samples belonged to the G3 genotype. Out of 21 samples from Turkey, 16 (76.2%) were G1 and 5 (23.8%) were G3, while out of 15 samples from Iran, 10 (66.7%) were G1 and 5 (33.3%) were the G3 genotype. None of the samples isolated from humans in Iran or from sheep in Turkey were G3. Overall, between the two countries, 18.18% of E. granulosus isolates in cattle, 41.66% of isolates in sheep, and 23.07% of human samples were identified as G3, and the others as the G1 genotype. The G3 genotype was not detected in human samples from Iran or sheep samples from Turkey.

CONCLUSION

The findings of the study revealed that the G1 genotype of E. granulosus s.s. is the predominant genotype in humans and livestock, both in Turkey and Iran. The ratio of the E. granulosus s.s. G1 to G3 genotype was 3.2 in Turkey and 2 in Iran. The study also further confirmed that the nad5 gene properly differentiated the G1/G3 isolates of E. granulosus from both humans and livestock.

Pulmonary hydatidosis genotypes isolates from human clinical surgery based on sequencing of mitochondrial genes in Fars, Iran

BACKGROUND

Cystic echinococcosis (CE)/hydatidosis is an important neglected parasitic zoonotic disease caused by the metacestode of Echinococcus granulosus s.l. The present study was designed to identify the pulmonary CE species/genotypes in isolated human underwent to surgery in our center in Southern Iran.

METHODS

The study population of this study were all patients in Fars province who were admitted to Namazi Hospitals for pulmonary hydatid cyst surgery. Thoracic surgery was performed in the thoracic ward and the cyst/s was removed by open surgery via posterolateral or lateral thoracotomy. DNA was extracted from the germinal layer or the protoscoleces. PCR technique was performed using the cytochrome C oxidase subunit1 (cox1) gene, and the products were sequenced.

RESULTS

A total of 32 pulmonary hydatid cyst samples were collected from 9 (28%) female and 23 (72%) male aged from 4 to 74 years old. A total of 18(56%) cyst/s were in the left lobe and 14 (44%) cysts in the right lobe. Sequence analysis of the cysts showed that 24 samples (75%) were E. granulosus s.s (G1-G3) genotype and 8 (25%) were E. canadensis (G6/G7) genotype.

CONCLUSION

E.granulosus s.s genotype was the most prevalent genotype followed by E. canadensis (G6/G7) genotype. There was no significant statistical correlation between cysts' size, location, genotype strain, and patients' age and gender.

Cystic echinococcosis in sheep and goats of Lebanon

Cystic echinococcosis (CE), a zoonotic disease caused by the species complex of Echinococcus granulosus sensu lato (s.l.), is endemic in Middle East and the Mediterranean basin, where pastoral activity is widespread. Despite the chronic endemicity of the disease in Lebanon and neighbouring countries, recent data are scant. The objectives of this survey were to evaluate the current epidemiology of CE in Lebanon, investigate the prevalence and determine the infecting genotypes in locally raised sheep and goats. A multidimensional approach combining post-mortem inspection of slaughtered animals and molecular diagnosis of the parasite was conducted to this end. From 2018 to 2020, 62.9% of the sheep and 20.9% of the goats were found positive for CE. The presence of hydatids varied between organs, showing higher prevalence in the liver of sheep vs the lungs of goats, however, a higher fertility rate of hydatid cyst was observed in lungs for both animals. Molecular diagnosis based on partial mitochondrial cox1 gene (795 bp) showed that the majority of isolates were identified as E. granulosus sensu stricto (98.7%) and only one isolate from goat was identified as Echinococcus canadensis (genotype G7; 1.3%). Echinococcus granulosus s.s. population among the sheep and goats was represented by 22 haplotypes having very little genetic differentiation and relatively moderate haplotype diversity. Population demographics explored through neutrality indices suggested expanding population within the intermediate hosts. These results document the high prevalence of CE in the livestock of Lebanon and reveal for the first time the presence of three different genotypes G1, G3 and G7.

Genotyping of the Echinococcus granulosus in Paraffin-Embedded Human Tissue Samples from Iran

PURPOSE

Cystic Echinococcosis (CE) is a medically important disease that is caused by the metacestodes of Echinococcus granulosus. Human hydatid is considered an endemic disease in specific regions of Iran. The goal of the present study was to determine the genetic diversity of E. granulosus from the paraffin-embedded human tissue samples which were collected from the endemic regions of Iran.

METHODS

Fifty-five formalin-fixed and paraffin-embedded hydatid cysts (FFPE) of humans, which had been removed surgically, were obtained from the South Khorasan and Sistan and Baluchistan provinces. These regions are related to the East and Southeast regions of Iran, respectively. The cox1 and nad1 genes from mitochondria were amplified from the extracted DNA and sequenced. The sequences were edited using the BioEdit software. Furthermore, phylogenetic and genetic diversity analyses were performed.

RESULTS

Sequencing of the cox1 and nad1 genes from the 44 CE samples was done successfully. Genetic analysis revealed that 38 (86.3%) and 6 (13.6%) of the isolates were G1- and G6-genotypes, respectively. In general, eight and six haplotypes were identified by cox1 and nad1 genes analysis, respectively. For G1 strains, the haplotype diversity index was higher for the cox1 gene (0.6 ± 0.07) in comparison with the nad1 gene (0.4 ± 0.09).

CONCLUSION

The findings of the present study showed that the sheep strain (G1) and the less important camel strain (G6) play the main roles in the transmission cycle of CE in the East and Southeast regions of Iran. Therefore, these results could be useful for managing the hydatid disease control programs in the studied and other similar areas.

Evaluation of zoonotic platyhelminthe infections identified in slaughtered livestock in Iran, 2015-2019

Background

Platyhelminth infections of livestock can result in considerable economic losses. This study aims to evaluate the spatial frequency of cystic echinococcosis (CE), dicrocoeliasis, and fascioliasis in livestock slaughtered in Iran during the years 2015–2019 and estimate direct costs associated with organ condemnation due to these parasites.

Methods

Abattoir data from 413 abattoirs representing all 31 Iranian provinces were collected from the Iran Veterinary Organization. Infection prevalence was calculated per year at the province level. The Local Moran’s I statistic was performed to evaluate spatial autocorrelation of animals positive at slaughter for the years 2015–2019. Direct costs associated with condemned livers were calculated for each parasitic condition, with costs associated with condemned lungs also included for CE.

Results

Overall prevalence values for the study timeframe were as follows: sheep and goat fascioliasis 1.56% (95% CI: 1.56–1.56%), cattle fascioliasis 3.86% (95% CI: 3.85–3.88%), sheep and goat dicrocoeliasis 4.63% (95% CI: 4.62–4.63%), cattle dicrocoeliasis 3.08% (95% CI: 3.07–3.09%), sheep and goat CE 5.32% (95% CI: 5.32–5.33%), and cattle CE 7.26% (95% CI: 7.24–7.28%). Northwest Iran had the highest prevalence of CE and fascioliasis. High infection areas for Dicrocoelium spp. included the provinces of Zanjan, Gilan, Qazvin, and Tehran, which are located in northern Iran. Direct economic losses for sheep and goat fascioliasis, dicrocoeliasis, and CE for the study period were US$13,842,759, US$41,771,377, and US$22,801,054, respectively. Direct economic losses for cattle fascioliasis, dicrocoeliasis, and CE for the study period were US$1,989,200, US$1,668,986, and US$2,656,568, respectively.

Conclusion

Our findings provide valuable data for future monitoring of these important parasitic diseases in Iranian livestock. Disease control strategies are required to reduce the economic and public health impact of these platyhelminths.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-02888-9.

The global status and genetic characterization of hydatidosis in camels (Camelus dromedarius): a systematic literature review with meta-analysis based on published papers

Hydatidosis is a potential zoonotic helminthic disease affecting a broad spectrum of mammals, including humans, worldwide. The current review was conducted to investigate the genotypic status and prevalence of hydatid disease in camels across the world. For the purpose of the study, the articles addressing the worldwide prevalence of hydatidosis in camels were searched in several English language databases. The search process resulted in the inclusion of 122 papers. Based on the data presented in the reviewed articles, the pooled prevalence of hydatid disease in camels across the world was measured at 23.75% (95% CI 20.15-27.55). Moreover, the subgroup analysis demonstrated significant differences in the overall prevalence of hydatidosis among camels based on year, geographic area, climate parameters, camel population, gender, infected organ, fertility rate of the cyst and laboratory diagnostic technique. Furthermore, the Echinococcus granulosus genotypes identified in camels with hydatidosis included G1, G2, G3, G1-G3, G5, G6, G7, G6-G7 and G6-G10, with G6 being the most common genotype throughout the world. The data obtained from the current study are central to the better conceptualization of the biological and epidemiological characteristics of E. granulosus s.l. genotypes around the world, which can be helpful in the planning and adoption of more comprehensive control strategies.

Molecular Characterization and Phylogeny of Taenia hydatigena and Echinococcus granulosus from Iranian Sheep and Cattle Based on COX1 Gene

Hydatid cyst, the larval stage of Echinococcus granulosus, and Cysticercus tenuicollis, the larval stage of Taenia hydatigena, are prevalent in domestic, livestock, and wild ruminants. The main goal of this research was to identify the isolates of E. granulosus and C. tenuicollis by partial sequencing with PCR amplification of the cytochrome C oxidase 1 (COX1) gene. During a routine veterinary inspection at a Chabahar city slaughterhouse, two samples of hydatid cysts from sheep's liver and cattle's lung and two samples of C. tenuicollis from sheep's liver were collected. After DNA extraction, the fragment of the COX1 gene was amplified by the PCR method. Sample sequences were modified and synchronized by Chromas and CLC genomic workbench 11 software. Sequence analysis was carried out by BLAST algorithms and GenBank databases. Phylogenetic trees were performed using MEGA 7 software and the neighbor-joining and maximum likelihood method for T. hydatigena and E. granulousus. The result indicated that the main genotype of parasites and the amplified fragment size were G1 and approximately 455 bp, respectively. The analysis of phylogenetic trees based on nucleic acid for four samples showed that there was a common ancestor. However, the shift in nucleotides in the two isolates in E. granulosus and the two isolates of T. hydatigena were non-synonymous type and synonymous type, respectively. The present study showed that the dominant genotype in all isolates was G1 and this report was similar to other studies in Iran and the world. Also, the partial COX1 gene sequence was matched with T. hydatigena.

First report on the phylogenetic relationship, genetic variation of Echinococcus shiquicus isolates in Tibet Autonomous Region, China

Background

Cystic or alveolar echinococcosis caused by the larval stages of Echinococcus spp. is a very severe zoonotic helminth infection. Echinococcus shiquicus is a newly discovered species that has only been reported in the Qinghai and Sichuan provinces of the Qinghai-Tibet plateau, China where, to date, it has only been confirmed in Tibetan foxes and wild small mammal populations of the Tibetan plateau. Information on its genetic and evolutionary diversity is scanty. The aim of this study was to investigate the prevalence of E. shiquicus in plateau pikas (Ochotona curzoniae), a known intermediate host, and to determine the genetic variation and phylogenetic relationship of the E. shiquicus population in the Tibet region of China based on mitochondrial DNA.

Methods

Echinococcus shiquicus samples were collected from Damxung and Nyêmo counties (located in Tibet Autonomous Region, China). The mitochondrial cox1 and nad1 gene sequences were analyzed, and the genetic diversity and epidemiology of E. shiquicus in the region were discussed based on the results.

Results

The prevalence of E. shiquicus in pikas in Damxung and Nyêmo counties was 3.95% (6/152) and 6.98% (9/129), respectively. In combination with previous public sequence data, the haplotype analysis revealed 12 haplotypes (H) characterized by two distinct clusters (I and II), and a sequence distance of 99.1–99.9% from the reference haplotype (H1). The diversity and neutrality indices for the entire E. shiquicus populations were: haplotype diversity (Hd) ± standard deviation (SD) 0.862 ± 0.035; nucleotide diversity (Hd ± SD) 0.0056 ± 0.0003; Tajima's D 0.876 (P > 0.05); and Fu’s F 6.000 (P > 0.05).

Conclusions

This was the first analysis of the newly discovered E. shiquicus in plateau pikas in the Tibet Autonomous Region of China. The neutrality indices suggest a deficiency of alleles, indicative of a recent population bottleneck.

Parasitic diseases of equids in Iran (1931-2020): a literature review

Parasitic infections can cause many respiratory, digestive and other diseases and contribute to some performance conditions in equids. However, knowledge on the biodiversity of parasites of equids in Iran is still limited. The present review covers all the information about parasitic diseases of horses, donkeys, mules and wild asses in Iran published as articles in Iranian and international journals, dissertations and congress papers from 1931 to July 2020. Parasites so far described in Iranian equids include species of 9 genera of the Protozoa (Trypanosoma, Giardia, Eimeria, Klossiella, Cryptosporidium, Toxoplasma, Neospora, Theileria and Babesia), 50 helminth species from the digestive system (i.e., 2 trematodes, 3 cestodes and 37 nematodes) and from other organs (i.e., Schistosoma turkestanica, Echinococcus granulosus, Dictyocaulus arnfieldi, Parafilaria multipapillosa, Setaria equina and 3 Onchocerca spp.). Furthermore, 16 species of hard ticks, 3 mite species causing mange, 2 lice species, and larvae of 4 Gastrophilus species and Hippobosca equina have been reported from equids in Iran. Archeoparasitological findings in coprolites of equids include Fasciola hepatica, Oxyuris equi, Anoplocephala spp. and intestinal strongyles. Parasitic diseases are important issues in terms of animal welfare, economics and public health; however, parasites and parasitic diseases of equines have not received adequate attention compared with ruminants and camels in Iran. The present review highlights the knowledge gaps related to equines about the presence, species, genotypes and subtypes of Neospora hughesi, Sarcocystis spp., Trichinella spp., Cryptosporidium spp., Giardia duodenalis, Blastocystis and microsporidia. Identification of ticks vectoring pathogenic parasites, bacteria and viruses has received little attention, too. The efficacy of common horse wormers also needs to be evaluated systematically.

Environmental, climatic and host population risk factors of human cystic echinococcosis in southwest of Iran

BACKGROUND

Cystic echinococcosis (CE), a worldwide zoonotic disease, is affected by various biological and environmental factors. We investigated dog/livestock populations, climatic and environmental factors influencing the distribution of human CE cases in Fars province, southwest Iran.

METHODS

We mapped the addresses of 266 hospitalised CE patients (2004-2014) and studied the effects of different temperature models, mean annual rainfall and humidity, number of frosty days, slope, latitude, land covers, close proximity to nomads travel routes, livestock and dog densities on the occurrence of CE using geographical information systems approach. Data were analyzed by logistic regression.

RESULTS

In the multivariate model predicting CE, living in an urban setting and densities of cattle and dogs were the most important CE predictors, sequentially. Dry (rained) farm, density of camel and sheep, close proximity to nomads travel routes, humidity, and slope also were considered as the determinants of CE distribution, when analyzed independently. Slope had a negative correlation with CE while temperature, frost days and latitude were not associated with CE.

CONCLUSIONS

In our study, an urban setting was the most important risk factor and likely due to a combination of the high density of key life cycle hosts, dogs and livestock, a large human susceptible population and the high number of abattoirs. Farmland and humidity were highly suggestive risk factors and these conditions support the increased survival of Echinococcus granulosus eggs in the soil. These findings support the development of strategies for control of disease. More research is needed test optimal interventions.

Current situation and future prospects of Echinococcus granulosus vaccine candidates: A systematic review

Cystic echinococcosis is a worldwide zoonotic disease, represents a threat for livestock and humans, manifests as a quiescent, subclinical and chronic hydatid cyst infection. The disease imposes high expenditures and economic losses in medical and veterinary. Prophylactic vaccination would be one of the effective preventive health care against echinococcosis. During the last decades, many studies have characterized the protective antigens of Echinococcus granulosus and their role in immunization of various animal host species. Herein, we aimed to systematically evaluate and represent the best antigens as possible vaccine candidates for cystic echinococcosis. Data were systematically searched from five databases including ProQuest, PubMed, Scopus, ScienceDirect and Web of Science, up to 1 February 2020. Two reviewers independently screened and assessed data extraction and quality assessment. A total of 47 articles were eligible for inclusion criteria in the current study. The most common antigens used for vaccination against E. granulosus were EG95 and antigen B. Freund's adjuvant and Quil A have been predominantly utilized. In addition, regarding the antigen delivery, animal models, measurement of immune responses and reduction in hydatid cyst have been discussed in the text. The data demonstrated that DNA vaccines with antigen B and recombinant protein vaccines based on EG95 antigen have the best results and elicited protective immune responses.

Serodiagnosis of human cystic echinococcosis based on recombinant antigens B8/1 and B8/2 of Echinococcus granulosus

BACKGROUND

Cystic echinococcosis (CE) is a widespread parasitic disease caused by the larval stage of Echinococcus granulosus. Since current methods for the diagnosis of CE are not efficient enough, rapid, and reliable tests are required for the acceleration of CE diagnosis. The present study aimed to produce recombinant B8/1 and B8/2 antigens of E. granulosus and evaluate their sensitivities and specificities separately and simultaneously for the diagnosis of CE.

METHODS

The recombinant B8/1 and B8/2 antigens were produced and used in an ELISA system for the diagnosis of CE. The sera specimens including 30 sera from pathologically confirmed CE patients, 30 from other non-CE patients, and 30 from healthy controls, were evaluated by the ELISA, using AgB8/1 and AgB8/2.

RESULTS

The results showed a sensitivity of 93.33%, 90%, and 96.7% for AgB8/1, AgB8/2, and their combination, respectively. The specificities were 91.7%, 93.33%, and 93.33% for AgB8/1, AgB8/2, and their combination, respectively.

CONCLUSION

Simultaneous usage of AgB8/1 and AgB8/2 increased the test sensitivity for the diagnosis of CE. Furthermore, the specificity of AgB8/1 and AgB8/2 combination was more than AgB8/1 and equal to AgB8/2 alone. The findings revealed that the simultaneous usage of AgB8/1 and AgB8/2 could be a suitable approach for the diagnosis of CE.

Molecular survey on cattle and sheep hydatidosis and first detection of Echinococcus canadensis (G6/G7) in sheep in Turkey

Larval stage of genus Echinococcus is the causing agent for the zoonotic infection which is life threatening known as Echinococcosis. The purpose of this study was the identification, molecular analysis and characterization of Echinococcus spp. in sheep and cattle. The sampling was done from slaughterhouse of Elazig, Turkey. A total of 85 isolates (sheep, n = 19 and cattle, n = 66) have been collected after slaughtering. Following the gDNA isolation and PCR products of mt-CO1 gene (446 bp) of all the samples were sequenced. Out of 85 isolates, 84 were recognized as Echinococcus granulosus sensu stricto and one sheep isolate was found as Echinococcus canadensis (G6/G7 ) which is identified for the first time in Turkey. However, single nucleotide polymorphism has been observed not only in samples of different animals but also in samples collected from the same cattle. Six liver and three lung hydatid cysts have been detected in cattle. Although no nucleotide differences have been observed in the liver samples, there was single nucleotide polymorphism (C→T) in 40th nucleotide of two lung cysts. As a result of haplotype analysis, 16 haplotypes of E. granulosus s.s. were detected in 66 cattle isolates whereas 7 haplotypes of E. granulosus s.s. were identified in 19 sheep samples.

Effects of geographical and climatic factors on cystic echinococcosis in south-western Iran

Cystic echinococcosis (CE) is caused by the larval form of Echinococcus granulosus that can cause serious health and economic problems in the endemic foci. CE is globally distributed in various climatic conditions from circumpolar to tropical latitudes. Iran is an important endemic area with a spectrum of weather conditions. The aim of this study was to determine the effects of geo-climatic factors on the distribution of livestock CE in south-western Iran (SWI) in 2016 to 2018. Data of livestock CE were retrieved from veterinary organizations of four provinces of SWI. The geo-climatic factors, including mean annual temperature (MAT), minimum MAT (MinMAT), maximum MAT (MaxMAT), mean annual rainfall (MAR), elevation, mean annual evaporation (MAE), sunny hours, wind speed, mean annual humidity (MAH), slope, frost days and land cover, were analysed using geographical information systems (GIS) approaches. The statistical analysis showed that MAR, frost days, elevation, slope and semi-condensed forest land cover were positively and MAE, MAT, MaxMAT, MinMAT and salt and salinity land cover were negatively correlated with CE occurrence. MAE was shown to be a predictive factor in the stepwise linear logistic regression model. In short, the current GIS-based study found that areas with lower evaporation were the main CE risk zones, though those with lower temperature and higher rainfall, altitude and slope, especially where covered with or in close proximity of semi-condensed forest, should be prioritized for consideration by health professionals and veterinarians for conducting control programmes in SWI.

Evaluation of Prognostic Factors Associated with Postoperative Complications Following Pulmonary Hydatid Cyst Surgery

Background:

Hydatid cysts are one of the serious complications following echinococcus infection. The liver and the lungs are the most affected organs, respectively. The severity of the disease is associated with the increase in the number and the size of the cysts, cysts rupture, and systemic effects. The aim of this study is to evaluate prognostic factors that are associated with the increased incidence of postoperative complications following pulmonary hydatid cyst surgery.

Methods:

Patients referred to Madani hospital from 2014-2018, presenting pulmonary hydatid cysts were included in this study. All the patients were evaluated based on the following parameters: age, gender, location and size of the cysts, rupture status of the cysts (intact or perforated), type of surgical intervention (capitonnage or segmentectomy) and Erythrocyte Sedimentation Rate (ESR). The factors were then compared with postoperative complications. Statistical analysis of the data obtained was conducted using R-software

Results:

Of 76 patients enrolled in our study, 52.63% were males and 47.36% were female. Air leak complication was reported in 13.15% of the patients and 3.94% of the patients were presented with pleural effusion. Postoperative complications were significantly associated with the perforated (ruptured) cysts p= 0.001, segmentectomy p= 0.013, giant hydatid cysts p= 0.007 and ESR p= 0.014. However, the side of the lung was not significantly related to postoperative complications.

Conclusion:

Our study reports that perforated cysts, increased size, segmentectomy and abnormal ESR are likely to increase postoperative complications following pulmonary hydatid cysts surgery. Prospective studies with perioperative parameters and greater sample size can help to deduce better inferences.

Sero-epidemiology of Hydatidosis Among General Population of Jolfa County, Northwestern Iran Using IHA, ELISA and Western Blot (2017-2018)

BACKGROUND

Human hydatidosis is mostly a latent and neglected disease with known endemicity in Iran.

AIMS

Due to the importance of this infection in the country and its latent nature, we aimed to evaluate the serological status of hydatid cyst in northwestern Iran.

OBJECTIVES

Herein, we evaluated the serological status of hydatid cyst in urban and rural inhabitants of Jolfa county, northwestern Iran during 2017-2018.

METHODS

In total, 1296 blood samples were obtained from human individuals and the presence of anti-E. granulosus antibodies was investigated using IHA, ELISA and WB.

RESULTS

Based on results, 25 IHA positive person were detected in the examined population, however ELISA test showed 14 of 25 IHA positive patients as negative. Also, 269 IHA negative fellows were shown as negative by ELISA. WB analysis of sera from 25 IHA positive subjects revealed consistent results with the ELISA test, and the most reactive SHCF Ag was a 37 KDa protein. The age-standardized seroprevalence of hydatidosis among Jolfa's general population was 1.12% with 95%CI: 1.02-1.20. Moreover, there existed a significant association between keeping/- contact with dogs (P = 0.022) as well as vegetable consumption (P < 0.001) with ELISA positive test results.

CONCLUSION

Along with such serological evidence in this region, we highly suggest physical examination and applying imaging techniques for suspected cases in the area for a better understanding of CE.

Control of Cystic Echinococcosis in Iran: Where Do We Stand?

Cystic echinococcosis (CE) is an important public health challenge in Iran that requires a One Health approach to control. Filling information gaps and research needs on different aspects of the disease, including parasite biology, disease ecology, human/animal infection, and administrative issues, is essential to address challenges faced by CE control programs.

Genetic Diversity of Echinococcus granulosus Isolated from Humans: A Comparative Study in Two Cystic Echinococcosis Endemic Areas, Turkey and Iran

Cystic echinococcosis (CE) is one of the most important zoonotic parasitic diseases caused by the larval stage of Echinococcus granulosus. Based on molecular studies and DNA sequencing, E. granulosus has been classified into 10 different genotypes (G1 to G10). Two neighboring countries, Turkey and Iran, are considered the two main foci of CE in the Middle East. The current study is aimed at examining the genotype diversity of E. granulosus isolated from human clinical samples in Turkey and Iran. Surgically removed human hydatid cysts were collected from East Azerbaijan and Fars provinces in Iran and Van province in Turkey. After extracting DNA, performing PCR, targeting the cox1 gene, the PCR products were purified from the gel and were sequenced from both directions. The sequences were aligned and compared, using BioEdit and also the BLAST program of GenBank. The maximum likelihood tree was constructed based on the Tamura-Nei model, using the MEGAX software. Phylogenetic analysis showed that the human isolated samples were classified into two major clades: G1 (from Iran and Turkey) and G3 (5 samples from northwestern Iran and one sample from Turkey). The mean and degree of genetic divergence (K2P) between the two major clades, G1 and G3, were 0.2% and 0.7 ± 0.4%, respectively. The findings of the current study revealed that the sheep strain (G1) and the less important strain G3 have major roles in the transmission cycle of CE in two neighboring countries, Iran and Turkey. Therefore, it is necessary to interpose the life cycle of this parasite and reduce the disease burden in livestock and humans by adopting common regional preventive and control policies.

Epidemiological and molecular studies on Echinococcus granulosus from free-roaming dogs in Southeast Iran

Background and Aim:

Cystic echinococcosis (CE), as a major zoonotic helminth infection, imposes remarkable socioeconomic burden on many endemic countries across the world, including Iran. Due to the high importance of free-roaming dogs in the transmission of CE, epidemiological and molecular studies in this type of hosts are required in the endemic regions. This study aimed to investigate the epidemiology and genotyping of Echinococcusgranulosus isolated from stray dogs in Kerman, Southeast Iran.

Materials and Methods:

Eighty-four samples were isolated from stray dogs in the city and suburbs of Kerman in coordination with the health authorities and the municipality office for rabies control and dog population management. Dog demographic data, including age and sex were collected. The worm was isolated by necropsy and genomic DNA was extracted and partial cytochrome c oxidase subunit 1 gene was amplified using specific primers. Phylogenetic and Templeton-Crandall-Sing (TCS) network analyses were carried out on the sequence data.

Results:

The overall prevalence of CE in the surveyed dogs was 10.7% (9/84 cases). Out of 84 stray dogs, 33 (39.3%) and 51 (60.7%) cases were male and female, respectively. There was not a statistically significant difference between the infection and gender of dogs. However, infection is shown more in dogs under one year of age with a statistically significant difference (p<0.05). The results of molecular studies indicated E. granulosus G1 genotype for all isolates. The high presence of free-roaming dogs in urban and peri-urban areas and high frequency of parasite in this animal is a risk factor for humans in the region. Haplotype sequence analysis on the dog isolates revealed a close relationship with other E. granulosus isolates in Kerman.

Conclusion:

The findings of this study provide evidence-based data about the epidemiological and molecular characteristics of CE in dog definitive hosts of Southeast Iran. Further studies are required to understand the prevalence and parasite genotypes in dogs in Iran.

Zoonotic parasites of dromedary camels: so important, so ignored

With a global population of about 35 million in 47 countries, dromedary camels play a crucial role in the economy of many marginal, desert areas of the world where they survive under harsh conditions. Nonetheless, there is scarce knowledge regarding camels' parasite fauna which can reduce their milk and meat productions. In addition, only scattered information is available about zoonotic parasites transmitted to humans via contamination (e.g. Cryptosporidium spp., Giardia duodenalis, Balantidium coli, Blastocystis spp. and Enterocytozoon bieneusi), as foodborne infections (e.g. Toxoplasma gondii, Trichinella spp. and Linguatula serrata) or by arthropod vectors (Trypanosoma spp.). Herein, we draw attention of the scientific community and health policy-making organizations to the role camels play in the epidemiology of parasitic zoonotic diseases also in the view of an increase in their farming in desert areas worldwide.

Epidemiology of echinococcosis in Iran: a systematic review and meta-analysis

BACKGROUND

Echinococcosis is a zoonotic disease caused by the larval stages of taeniid cestodes of the genus Echinococcus. The two major types of infection in humans are cystic echinococcosis (CE) or hydatidosis and alveolar echinococcosis (AE). It is endemic in some parts of the world, such as the Middle East, with Iran being a part of it. This systematic review and meta-analysis were conducted to determine the prevalence of CE and AE echinococcosis and their epidemiological and clinical aspects in Iran.

METHODS

Electronic databases, including MEDLINE (via PubMed), SCOPUS, Web of Science, SID and Mag Iran (two Persian scientific search engines) were searched from 1 January 1990 to 8 August 2017. The prevalence of CE and AE echinococcosis was estimated using the random effects meta-analysis. Heterogeneity was evaluated by subgroup analysis. Data were analyzed by STATA version 12.

RESULTS

Of the 2051 records identified in the mentioned electronic databases, Seventy-eight articles met our eligibility criteria, with a total of 214124individuals. The meta-analysis was performed on only 37 out of 78 included studies. The pooled prevalence of CE and AE in Iran was 5% [95% confidence interval )CI(: 3-6%] and 2% [95% CI: 0-5%], respectively. Subgroup meta-analysis revealed that the prevalence of CE was significantly higher in North [9%, 95% CI: 4-18%] and West of Iran [6%, 95% CI: 3-11%], patients younger than 40 years of age [7%, 95% CI: 4-12%], villagers and nomads [6%, 95% CI: 2-12%], and studies that used the combination of serological, clinical, and imaging diagnostic methods [7%, 95% CI: 5-9%]. There were no significant differences between the prevalence of CE among low and high-quality studies. Housewives were the most affected group by hydatidosis (n=24/77, 31%), followed by illiterate people (n=11/77, 14%) and farmers (n= 9/77, 12%). Liver [55%, 95% CI: 46-65%] and lung [28%, 95% CI, 22-35%] were the most common sites of cyst formation.

CONCLUSIONS

Given to the importance of echinococcosis on human health and domestic animals industry, it is necessary to implement monitoring and control measures in this regard.