Global epidemiology and spatial distribution of Toxoplasma gondii in goats: Protocol for a systematic review and Bayesian hierarchical meta-analysis

BACKGROUND

Toxoplasma gondii, a cosmopolitan protozoan parasite causes toxoplasmosis in humans and many species of domestic and wild animals. T. gondii instigates significant economic losses in sheep and goat farming industry and can lead to abortion, stillbirth, congenital malformations and neonatal losses. The objective of this protocol is to evaluate worldwide seroprevalence of T. gondii exposure in goats using Bayesian hierarchical meta-analysis and geographic information system (GIS).

METHODS

A comprehensive literature search will be conducted using search engines, including Web of Science, ScienceDirect, Scopus, PubMed, ProQuest, EMBASE, PROSPERO Register and, Google Scholar without date and language restrictions. The authors search for cross-sectional studies that determine the seroprevalence of T. gondii in goats. Two reviewers will independently screen, selected studies; also, they will extract data, and assess the risk of bias. In case(s) of disagreement, a consensus will be reached with the help of a third author. The Bayesian hierarchical meta-analysis will use to estimate country and worldwide true seroprevalence of T. gondii, which is consist of the sensitivity and specificity of the applied serological assays. The obtained data will be used to identify country-level risk factors associated with T. gondii exposure using GIS in the ArcGIS software.

DISCUSSION

The systematic review produced from this protocol will provide the true prevalence rate and spatial distribution T. gondii exposure in goats both regionally and globally using Bayesian hierarchical and GIS analysis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42020107928.

Prevalence of Ecto and Gastrointestinal Parasites of Rattus rattus in Mazandaran Province, North of Iran

Objective

Rodents act as reservoir hosts and are an important potential source for many zoonotic pathogens such as parasites, which pose a public health risk to humans. Therefore, it is necessary to investigate the prevalence of parasites among rodents.

Methods

A total of 118 Rattus rattus were captured in Mazandaran province, north of Iran, using snap live traps. Various samples were collected from feces and each rat was combed with a fine-tooth comb to extricate any ectoparasite. Fecal specimens were examined by direct wet mounting, formalin-ether concentration, modified acid-fast, and trichrome staining methods.

Results

The overall prevalence of gastrointestinal parasites in the examined rats was 75.4%. Cryptosporidium spp. (30.5%) were the most prevalent protozoan, followed by Giardia spp. (20.3%), Entamoeba muris (13.5%), Trichomonas muris (10.1%), and Spironucleus muris (3.3%). Regarding helminths' eggs, Syphacia obvelata (24.5%), Hymenolepis diminuta (10.1%), and Trichuris muris (9.3%) had the highest prevalence, respectively. Furthermore, 3060 ectoparasites collected from 102 rodents were infested with lice (40% Polyplax spp.), mites (33.3%), and flea (16.1% Xenopsylla cheopis and 10.6% Xenopsylla astia).

Conclusion

According to the results of this study, the prevalence of ecto and gastrointestinal parasites in the collected rats in the area being studied was remarkably high. Additionally, Rattus rattus can be considered a potential risk to human health.

Identification and multilocus genotyping of Toxoplasma gondii isolates from congenital infection in north of Iran

Congenital toxoplasmosis can cause severe consequences in the fetus, such as spontaneous abortion which is affected by parasite strain. Also, recent studies revealed the high genetic diversity of Toxoplasma gondii. This study aims to investigate the serological status of T. gondii in pregnant women, multilocus genotyping in aborted fetuses' tissue, and archived formalin-fixed paraffin-embedded placenta. This study was performed on 100 pregnant women with spontaneous abortion and their aborted fetuses, and 250 of the archived placentae in Iran. The blood and tissue were examined for seroprevalence and genotype determination of T. gondii using ELISA and multilocus nested-PCR-RFLP, respectively. Anti-T. gondii IgG and IgM were detected in 68 samples (68%) and 1 (1%) out of 100 serums. Toxoplasma DNA was identified in 1 (1%) aborted fetuses' tissue and 32 (12.8%) placenta samples. Overall, ten positive DNA samples were successfully genotyped, and five genotypes were recognized (ToxoDB#1, #2, #10, #27, and #48). The obtained results indicated congenital toxoplasmosis is a severe risk in this region. As type I is highly pathogen and can lead to severe complications, the prevention of the infection should be considered in seronegative pregnant women.

Genetic characterization of Toxoplasma gondii in meat-producing animals in Iran

BACKGROUND

The consumption of uncooked or undercooked food from infected intermediate hosts can result in Toxoplasma gondii infection in humans. However, few studies have investigated the genetic diversity of this protozoan parasite in Iran. The aim of the present study was to genetically characterize isolates of T. gondii from intermediate host animals in Mazandaran Province, Iran.

METHODS

Blood and heart tissue samples were collected from 204 ruminants, and brain tissue was collected from 335 birds. The prevalence of T. gondii infection in these samples was determined serologically using the modified agglutination test and by conventional PCR assays. Those PCR samples positive for T. gondii DNA and 13 DNA samples extracted from aborted fetuses in a previous study were genotyped with 12 genetic markers using the multilocus-nested PCR-restriction fragment length polymorphism (Mn-PCR-RFLP) technique.

RESULTS

Antibodies for parasites were found in 35.7% of the ruminant (39.1% of sheep and 26.4% of goats) samples and in 51.3% of the bird (100% of geese, 52.3% of free-range chickens and 46% of ducks) samples. Molecular detection by PCR of the repetitive 529-bp DNA fragment revealed contamination of 13.2% of ruminant (14.6% of sheep and 9.4% of goats) samples and of 9.6% of bird (11.1% of chickens, 5.7% of ducks and 0% of geese samples). The results from 30 DNA samples revealed five ToxoDB (genome database for the genus Toxoplasma) PCR-RFLP genotypes, including #1 (Type II), #2 (Type III), #10 (Type I), #27 and #48, with genotype #1 the most predominant.

CONCLUSIONS

As evidenced by the results of this study, ruminants and birds are infected with T. gondii in the region, suggesting that they are likely to be involved in the transmission of T. gondii to humans through meat consumption. The identification of different genotypes may suggest a higher genetic diversity of this parasite in Mazandaran, reflecting local environmental contamination. These results have important public health implications for the prevention and control strategies of infection.

More than Seventy Years of Research (1948 –November 2021) on Toxoplasma gondii in Iran: A Narrative Review

In this review, we intend to provide a summary of the activities of researchers in the field of Toxoplasma gondii in Iran, during the past 70 years. Most studies have been limited to epidemiological studies (mostly using ELISA and IFA methods). Designing a standard and reliable method using the specific antigens of this parasite is essential. So far, studies in the field of drug effects have not been able to introduce an effective drug with few side effects. Various types of vaccines have been developed, such as recombinant and DNA vaccines. However, none of them had a good efficacy. The use of multi-epitope vaccines as potential vaccines against toxoplasmosis is recommended. At present, limited studies have been conducted on the patterns of transmission and genetic diversity of isolated isolates in Iran. Future research to determine the genotype of T. gondii could play an important role in the study of population structure, and biological characteristics of this parasite. It is hoped that the results of this study will help control, prevent, and reduce the burden of disease caused by this parasite.

Molecular Identification of Trichostrongylus Species Among Small Ruminants in Mazandaran Province, Iran

Background: Trichostrongylus is an intestinal parasite that is highly prevalent in humans and livestock worldwide. There is limited information about the prevalence and epidemiology of Trichostrongylus species among the infected livestock in Mazandaran Province, northern Iran. This study aimed to identify Trichostrongylus spp. among small ruminants using morphometric and molecular methods. Materials and Methods: Small intestinal organs of sheep and goats, slaughtered in Mazandaran Province, were examined for infectivity with Trichostrongylus parasites. Primary species identification was conducted based on the morphological characterization of the male worms. The internal transcribed spacer (ITS) II regions of the ribosomal DNA of the worm tissues were amplified using the polymerase chain reaction (PCR) assay and then the product was subjected to sequencing. Subsequently, the PCR products of the ITS II region were subjected to digestion by HinfI and DraI restriction enzymes using the PCR-restriction fragment length polymorphism (RFLP). Results: Of 180 samples, 98 (54.44%) were confirmed positive for Trichostrongylus based on the conventional PCR. The digestion of the PCR products with HinfI and DraI facilitated the identification of three Trichostrongylus species, namely Trichostrongylus colubriformis (35%, 90.81%), Trichostrongylus axei (4%, 4.08%), and Trichostrongylus vitrinus (5%, 5.1%). Both morphometric and RFLP techniques resulted in the differentiation of the three Trichostrongylus species. Conclusion: The present study was the 1st attempt in the last 30 years for the identification of Trichostrongylus species in small ruminants in Mazandaran Province. The findings of this study can be helpful for epidemiological and ecological studies, the establishment of effective control programs, and the management of gastrointestinal parasites in Mazandaran Province.

Association between Toxoplasma gondii Infection and Headache: A Systematic Review and Meta-Analysis

BACKGROUND

The impact of infectious agents, such as Toxoplasma gondii (T. gondii), on human behavior and mental disorders, has recently attracted the attention of researchers. T. gondii has emerged as a suitable candidate for such disorders due to its neutral nature. Therefore, the current study aimed at investigating the possible relationship between T. gondii infection and headache.

METHODS

Five databases were thoroughly searched (up to October 4, 2019) for articles on the prevalence of T. gondii in headache sufferers. In this study, the odds ratio (OR) and corresponding 95% confidence interval (CI) were estimated using a random effect model and forest plot to gauge effect size and effect of each study.

RESULTS

A total number of four articles, including one cross-sectional and three case-control studies 2517 participants, entered the meta-analysis, out of whom, 1205 subjects were afflicted with headache or migraine (17.67% positive for toxoplasmosis) and 1312 participants were not (18.29% for toxoplasmosis). The results of the meta-analysis indicated a common OR of 1.59 (95% CI: 1.03-2.47) by the random effect model.

CONCLUSION

The obtained results of several studies have linked toxoplasmosis and headache. Therefore, more quality studies with larger sample sizes are needed to determine the detailed association between headache and T. gondii infection for the prevention and control of toxoplasmosis among headache sufferers.

Molecular Identification of Neospora caninum Infection in Aborted Fetuses of Sheep, Cattle, and Goats in Mazandaran Province, Northern Iran

Background:

We aimed to identify Neospora caninum DNA in the brain samples of aborted fetuses of cattle, goats, and sheep in Mazandaran, northern Iran, using PCR.

Methods:

In total, 133 aborted fetuses (51 sheep, 78 cattle, and 4 goats) were randomly collected from different stages of gestation in various regions of Mazandaran, Iran, from Mar 2016 to May 2017. The DNA was extracted from all the brain samples using phenol chloroform isoamyl alcohol instructions. The Nc-5 gene was used for the detection of N. caninum DNA by nested-PCR assay.

Results:

The detection of N. caninum DNA was confirmed by the observation of a 227 bp band in 24 samples of 133 aborted fetuses (18.1%). The highest prevalence rate of N. caninum was detected in the cattle (20.5%) followed by the sheep (15.6%); however, no positive cases were reported in the goats. The highest and lowest prevalence rates of the infection were reported as 23.8% and 8.6% in Qaemshahr, and Behshahr, respectively. The prevalence rate of infection (32%) in the early gestational period was higher than those in the middle (15%) and late (3.8%) gestational periods.

Conclusion:

The obtained data of the present study indicated that N. caninum infection may partly be responsible for abortion and economic loss in livestock farming in Mazandaran Province.

Diagnosis of Toxoplasmosis in Ruminants Aborted Fetuses in Northern Iran Using Molecular and Bioassay Techniques

Background:

Toxoplasma gondii is a zoonotic obligatory intracellular protozoan parasite that infects a wide range of warm-blooded species. This study aimed to obtain further information on the role of T. gondii infection in ruminant abortion (sheep, goats and cattle) using bioassay and PCR methods in Mazandaran province, northern Iran.

Methods:

Overall, 104 aborted fetuses (52 bovine, 48 ovine, 4 caprine) were collected at different stages of gestation during the lambing seasons in various parts of Mazandaran Province from Mar 2016 to May 2017. Brains of 104 aborted fetuses were bioassayed in female BALB/c mice. DNA was extracted from all brain samples using phenol-chloroform-isoamyl Alcohol instructions. RE gene was used for detection all of T. gondii DNA by conventional PCR assay.

Results:

The results of the bioassayed samples were negative because no tachyzoites or cyst were observed in the peritoneal and brain specimens of the mice. The detection of T. gondii DNA was confirmed by observation of a 529 bp band in 15 out of 104 fetuses (14.4%). The highest prevalence rate of T. gondii detected from sheep (16.6%) followed by cattle (13.4%) and goats (0%). The highest prevalence of the infection was observed in east area, while the lowest prevalence of the infection was observed in west area.

Conclusion:

T. gondii infection may partly be responsible for abortion and economic losses in livestock husbandry in this region. Therefore, further additional researches such as genotyping T. gondii and designing control strategies for improving management in livestock flocks are necessary.

Toxoplasmosis among cancer patients undergoing chemotherapy: a population study based on the serological, molecular and epidemiological aspects

BACKGROUND

Toxoplasmosis is highly prevalent in northern Iran and immunocompromised individuals are more susceptible to this infection. The present study aimed to determine the seroprevalence, parasitism and genetic diversity of Toxoplasma gondii among patients with cancer undergoing chemotherapy in northern Iran.

METHODS

A total of 350 serum samples obtained from cancer patients were collected from laboratory centers in northern Iran. Immunodiagnosis and DNA detection were accomplished by ELISA and PCR. Thereafter, multiplex-nested PCR-restriction fragment length polymorphism was used for the genotyping of T. gondii.

RESULTS

In general, out of 350 patients, 264 (75.4%) and 9 (2.57%) cases were positive for anti-T. gondii IgG and IgM, respectively. Moreover, 19 (5.43%) samples contained T. gondii DNA. From 19 positive samples, 10 high-quality samples with sharp and non-smear bands were selected to determine the genotypes of T. gondii. Accordingly, the samples were classified as genotype #1 (type II clonal; n=4, 40%), genotype #2 (type III clonal; n=3, 30%), genotype #10 (type I clonal; n=2, 20%) and genotype #27 (type I variant; n=1, 10%).

CONCLUSIONS

As evidenced by the results, due to the high prevalence of T. gondii, cancer patients in northern Iran are at serious risk of severe toxoplasmosis and its complications. Therefore, oncologists need to regard this critical health problem as a matter requiring urgent attention.

Copro-molecular diagnosis of the Toxoplasmatinae subfamily in dog and cat populations in northern Iran

OBJECTIVES

The oocysts of the Toxoplasmatinae subfamily (Neospora caninum, Hammondia hammondi and H. heydorni, and Besnoitia besnoiti) are morphologically similar to Toxoplasma gondii, and indistinguishable from each other. This study investigated the prevalence of the Toxoplasmatinae subfamily in dog and cat fecal samples using a nested polymerase chain reaction method.

METHODS

Overall, 200 fecal samples from domestic dogs (n=120) and cats (n=80) were collected from 15 farms in northern Iran. The samples were homogenized in 2.5% potassium dichromate solution and subsequently concentrated with sucrose solution. DNA was extracted from samples using a genomic DNA kit. Specific primers and the 18S rDNA gene were used to screen and detect all Toxoplasmatinae oocysts.

RESULTS

Overall, 2.5% (3 of 120) and 22.5% (18 of 80) of the fecal samples collected from dogs and cats were infected with Toxoplasmatinae. In dogs, 2 samples were positive for N. caninum and 1 sample was positive for T. gondii. In cats, all 18 positive samples belonged to T. gondii. No contamination with H. heydorni was observed in dog fecal samples or H. hammondi and B. besnoiti in cat fecal samples. A phylogenetic analysis revealed that the T. gondii (cat) and N. caninum (dog) found had similarities with parasites reported from other regions of the world.

CONCLUSIONS

This is the first study to provide data on the epidemiology of Toxoplasmatinae oocysts in Iran. The findings suggest that public-health monitoring for the effective control of feces from cats and dogs and improved pet hygiene habits are needed.

Evolutionary puzzle of Toxoplasma gondii with suicidal ideation and suicide attempts: An updated systematic review and meta-analysis

The World Health Organization has reported an annual global suicide rate of 14.5 per 100,000 people. On the other hand, it is estimated that approximately one-third of the global population are infected with Toxoplasma gondii (T. gondii) parasite. It is widely assumed that microbial pathogens, such as T. gondii, are probably associated with affective and behavioural modulation. The present article aimed to assess the proposed role of toxoplasmosis in raising the risk of suicidal ideation (SI) and suicide attempts (SA) using the available epidemiological data. Seven major electronic databases and the Internet search engine Google were searched for all the studies published between the 1st of January 1950 and 31st of October 2019. The heterogeneity and the risk of bias within and across studies were assessed. Following data extraction, pooled odds ratios (ORs) with 95% confidence interval (CI) across studies were calculated using the random-effects models. A total number of 9,696 articles were screened and 27 studies were regarded as eligible in our systematic review (SI with five papers and 22 papers on SA). A significant association was detected between antibodies against T. gondii with TA (ORs = 1.57; 95% confidence interval [CI] 1.23-2.00, p = .000). Exploration of the association between T. gondii and SA yielded a positive effect of seropositivity for IgG antibodies but not IgM. Despite the limited number of studies, a statistical association was detected between suicidal behaviours and infection with latent T. gondii.

Relationship between toxoplasmosis and autism: A systematic review and meta-analysis

Toxoplasma gondii (T. gondii) is a foodborne parasite that is investigated in many psychiatric diseases, such as autism spectrum disorders (ASD). Therefore, a systematic literature review was conducted searching seven electronic databases on the prevalence of T. gondii antibodies among autism patients. The current study involved sensitivity analysis, meta-regression, subgroup analysis, publication bias test, and quality assessment of studies. On the basis of the findings, the odds ratio (OR) of latent Toxoplasma infection 1.93 (95% confidence intervals (CI): 1.01-3.66) was associated with ASD risk. However, there was no relationship between acute infection and ASD 0.39 (95% CI: 0.18-0.87). The obtained results of Begg's and Egger's tests showed no publication bias (P = 0.851 and P = 0.297, respectively). The sensitivity analysis confirmed robust and stable estimates with a significant level of heterogeneity (I² = 78.1%, P < 0.000). Of the investigated patients' characteristics, only the gender variable was analyzed, indicating the combined ORs of 2.63 (95% CI: 0.29-23.63) in females and 2.62 (95% CI: 0.94-7.30) in male participants. This study showed that toxoplasmosis plays an important role as a risk factor for autism. However, further prospective investigations are highly recommended to illuminate the developmental pathways to this disorder and provide new strategies for the prevention and treatment of this disease.

Toxoplasma gondii infection and risk of attention-deficit hyperactivity disorder: a systematic review and meta-analysis

Toxoplasma gondii (T. gondii), as an opportunistic neurotropic parasite of the Apicomplexa family, was firstly described in 1908. As attention-deficit hyperactivity disorder (ADHD) is one of the most common neuropsychiatric disorders in children and adolescents and often persists into adulthood, the purpose of this systematic review and meta-analysis was to investigate the relationship between T. gondii infection and ADHD.The data were systematically collected from seven electronic databases up to May 1^st 2019 with no language restriction. This study was registered at the International Prospective Register of Systematic Reviews (PROSPERO; code: CRD42020149353). Odds ratios (ORs) and 95% confidence intervals (CI) were estimated using a random effects model. Seven studies involving five cross-sectional and two case-control studies were included in this meta-analysis.Results indicated that there was a statistically non-significant association between exposure to T. gondii infection and increased risk of ADHD based on the detection of immunoglobulin G (IgG) antibody (2.02 [95% CI: 0.97-4.20]; I²=58.7%). However, obtained results of Egger's tests for anti-T. gondii IgG antibody showed publication bias (P=0.014).Sensitivity analysis revealed stable results for the association between anti-T. gondii IgG antibody with ADHD.Given the small number of studies in this field and the obtained results, it cannot be conclusively stated that T. gondii is a risk factor for ADHD.It is important to have reliable information about the relationship between T. gondii and ADHD around the world; as it may lead to better insight to elucidate the possible association of toxoplasmosis and the pathogenesis of ADHD.

The global seroprevalence of anti-Toxoplasma gondii antibodies in women who had spontaneous abortion: A systematic review and meta-analysis

BACKGROUND

Toxoplasma gondii (T. gondii) is an intracellular pathogen that can lead to abortion in pregnant women infected with this parasite. Therefore, the present study aimed to estimate the global seroprevalence of anti-T. gondii antibodies in women who had spontaneous abortion based on the results of published articles and evaluate the relationship between seroprevalence of anti-T. gondii antibodies and abortion via a systematical review and meta-analysis.

METHODS

Different databases were searched in order to gain access to all studies on the seroprevalence of anti- T. gondii antibodies in women who had spontaneous abortion and association between seroprevalence of anti-T. gondii antibodies and abortion published up to April 25th, 2019. Odds ratio (OR) and the pooled rate seroprevalence of T. gondii with a 95% confidence interval (CI) were calculated using the random effects model.

RESULTS

In total, 8 cross-sectional studies conducted on 1275 women who had abortion in present pregnancy, 40 cross-sectional studies performed on 9122 women who had a history of abortion, and 60 articles (involving 35 cross-sectional studies including 4436 women who had spontaneous abortion as case and 10398 as control and 25 case-control studies entailing 4656 cases and 3178 controls) were included for the final analyses. The random-effects estimates of the prevalence of anti-T. gondii IgG antibody in women who had abortion in present pregnancy and women who had a history of abortion were 33% (95% CI: 17%-49%) and 43% (95% CI: 27%-60%), respectively. In addition, the pooled OR for anti-T. gondii IgG antibody in cross-sectional and case-control studies among women who had spontaneous abortion were 1.65 (95% CI: 1.31-2.09) and 2.26 (95% CI: 1.56-3.28), respectively. Also, statistical analysis showed that the pooled OR of the risk of anti-T. gondii IgM antibody 1.39 (95% CI: 0.61-3.15) in cross-sectional and 4.33 (95% CI: 2.42-7.76) in case-control studies.

CONCLUSION

Based on the results of the current study, T. gondii infection could be considered a potential risk factor for abortion. It is recommended to carry out further and more comprehensive investigations to determine the effect of T. gondii infection on abortion to prevent and control toxoplasmosis among pregnant women around the world.

A serological investigation and genotyping of Toxoplasma gondii among Iranian blood donors indicates threat to health of blood recipients

BACKGROUND

Toxoplasmosis is a zoonotic disease in animals and human caused by the intracellular obligatory protozoan named Toxoplasma gondii. The purpose of this study was to evaluate the sero-molecular prevalence and genotyping T. gondii among healthy blood donors in north of Iran.

METHODS

In this cross-sectional study, 400 blood donors participated from all Blood Transfusion Organization (BTO) in Mazandaran province during October and November 2014. The blood samples were investigated for seroprevalence, DNA detection and genotyping of T. gondii using ELISA, nested-PCR, and Multilocus nested-PCR-RFLP methods respectively.

RESULTS

Among all of blood donors, 294 (73.5 %) and 9 (2.2 %) cases were seropositive for anti-T. gondii IgG and IgM antibodies. T. gondii DNA was detected in 7 samples. Four genotype of T. gondii were identified in blood donors samples (Genotype ToxoDB#1, #2, #10 and #27), which 50 % of T. gondii strains were highly pathogenic.

CONCLUSIONS

Taking into account survive T. gondii in blood transfusion bag, the high prevalence of T. gondii and existence of pathogenic genotypes in Iranian blood donors, it seems that T. gondii screening should be performed at the BTO to prevent complications of toxoplasmosis in blood recipients.

Cryptococcus and cryptococcosis in Iran during 1969-2019: A systematic review and meta-analysis

OBJECTIVE

Limited data are available on the epidemiology and etiology of cryptococcal infections in the Middle East. We aimed to conduct the systematic review and meta-analysis to summarize the epidemiological data on prevalence of Cryptococcus species complexes in trees and their surroundings, bird guano and secretions, animals, and highlight the reported episodes of cryptococcosis in Iran.

MATERIALS AND METHODS

Twelve databases, including PubMed, Science Direct, Scopus, Proquest, Google Scholar, Embase, and the ISI Web of Science, as well as the national databases, from January 1969 to October 2019 were searched. Furthermore, gray literature (e.g., thesis, congress abstracts) was evaluated using Iran Doc and www.thesis.

RESEARCH

ac.ir. Search process was accomplished on English or Persian language articles using the following keywords: "Cryptococcus", "Cryptococcosis", "invasive fungal infection", "Humans", "Birds", "Pigeon", "Animals", "Tree", "Eucalyptus", and "Iran", both alone and in combination.

RESULTS

Overall 36 studies were eligible regarding Cryptococcus and cryptococcosis in Iran. The total prevalence rates of Cryptococcus species in the tree was 4.7% (95% CI: 2.3-7.8), and in bird guano was 20.4% (95% CI: 10.7-32.2). Cryptococcosis in animal, and human were 1.7% (95% CI: 0.01-5.1), and 2.8% (95% CI: 0.7v6.1), respectively. The highest prevalence of Cryptococcus in the trees (14.6%), and bird guano (89.4%) in Khorasan, animals (8.9%) in Chaharmahal and Bakhtiari, and human (4.4%) in Mazandaran provinces were reported.

CONCLUSIONS

Given the significant risk of Cryptococcus species for susceptible humans, mainly HIV-infected patients, it seems quite necessary to adopt concrete preventive strategies to pinpoint the environmental habitats of this yeast.

A systematic review of Toxoplasma gondii genotypes and feline: Geographical distribution trends

Toxoplasma gondii (T. gondii) is well known for its ability to virtually infect all warm-blooded vertebrates. Although felines as the definitive hosts have an important role in the epidemiology of toxoplasmosis, there are few descriptions of genetic diversity in the world. The present review study aimed to describe the population structure of T. gondii in these animal species. For the purpose of the study, five English language databases reporting data on T. gondii genotyping in cats were searched within March-June 2019. This study is registered on the site of CAMARADES-NC3Rs (15-Jan-2018). The searching process resulted in the inclusion of 50 reports published from 1992 to June 2019. The data revealed that 47,390 samples were genotyped into 662 T. gondii DNA/isolates. Globally, atypical genotypes were predominant (47.7%, n = 316); in addition, Type II clonal strains were the second most common genotype (37%, n = 244). These results suggested an epidemic population structure in America and Asia, and a clonal population structure in Europe and Africa. Genotype #3 was found to be dominant in Africa, Europe and Oceania continents. Furthermore, genotypes #9 and #5 were prevalent in Asia and America, respectively. Additionally, genotypes #2, #3, #5 and #20 were common genotypes in domestic and sylvatic cycles from family Felidae. Collectively, this systematic review indicated a large degree of genetic diversity and circulation of mouse-virulent T. gondii strains in this family. However, further studies are necessary to better understand the population structure of T. gondii in these animal species and determine the significance of their features.

Congenital toxoplasmosis among Iranian neonates: a systematic review and meta-analysis

Toxoplasmosis is a serious zoonotic disease that can lead to abortion and congenital disorders and has a widespread global distribution in humans and animals. The objective of this review was to investigate the incidence of toxoplasmosis in Iranian neonates in order to obtain a comprehensive assessment of the overall situation of the disease for use in developing future interventions. Original studies investigating the incidence of Toxoplasma gondii infections in Iranian neonates were systematically searched in a number of English-language and Persian-language electronic databases. The search process resulted in the inclusion of a total of 11 studies in the systematic review, 10 of which were entered into the meta-analysis. The reviewed articles included 2,230 Iranian neonates investigated through January 1, 2018. Based on the retrieved studies, the overall weighted incidence rates of toxoplasmosis in the Iranian neonatal population and neonates with suspected congenital toxoplasmosis were estimated to be 0.64% (95% confidence interval [CI], 0.31 to 1.09) and 4.10% (95% CI, 2.68 to 5.77), respectively, using a fixed-effects model. The findings of the reviewed studies demonstrate that the incidence of toxoplasmosis is high in Iranian neonates. Accordingly, it can be concluded that toxoplasmosis is a serious public health concern that has been ignored by the Ministry of Health. Therefore, it is essential to perform further studies, in addition to implementing screening and detection programs, using standardized methods to estimate the incidence of toxoplasmosis in Iran and to determine its associated risk factors.

Aetiology of livestock fetal mortality in Mazandaran province, Iran

In the farming industry, the productivity of livestock herds depends on the fertility efficiency of animals. The accurate diagnosis of a broad range of aetiological agents causing fetal death is often difficult. Our aim was to assess the prevalence rates of Toxoplasma gondii, Neospora caninum, and Brucella spp. infections in ruminant abortion using bacteriological culture and molecular techniques in Mazandaran Province, northern Iran. Samples were collected from 70 aborted sheep, goat, and cattle fetuses between September 2014 and December 2015. Necropsy was performed on all the received samples, and brain tissue and abomasal content were obtained from the aborted fetuses. Protozoan infections were detected by specific polymerase chain reaction (PCR) and bacterial agents using bacteriological examinations and PCR assay. Infectious pathogens were detected in 22 out of 70 (31.4%) examined fetuses. Moreover, T. gondii, N. caninum, and B. melitensis were verified in 13 (18.6%), four (5.7%), and two (2.85%) samples, respectively. Our results showed that infection with the mentioned pathogenic agents may lead to fetal mortality, which can be a major cause of economic loss. The listed pathogens could be considered important etiological agents of fetal loss in Mazandaran Province, for which appropriate control measures such as vaccination and biosecurity can be implemented to prevent infection and reduce reproductive loss in livestock farms.

The potential risk of toxoplasmosis for traffic accidents: A systematic review and meta-analysis

Toxoplasmosis is a prevalent infectious disease. Although most people infected by Toxoplasma gondii are asymptomatic, evidence has suggested that this disease might affect some aspects of a host's behavior and associate with schizophrenia, suicide attempt, changes in various aspects of personality, and poor neurocognitive performance. These associations may play roles in increasing the risk of a number of incidents, such as traffic accidents, among infected people. In this regard, this study aimed to provide summary estimates for the available data on the potential risk of toxoplasmosis for traffic accidents. To this end, using a number of search terms, i.e. toxoplasmosis, Toxoplasma gondii, traffic accident, road accident, car accident, crash, and prevalence, literature searches (up to October 1, 2017) were carried out via 6 databases. The meta-analysis was conducted using the StatsDirect statistical software and a P-value less than 0.05 was regarded as significant in all statistical analyses. Out of 1841 identified studies, 9 studies were finally considered eligible for carrying out this systematic review. Reviewing results of these studies indicated that 5 out of 9 studies reported a significant relationship between Toxoplasma gondii and traffic accidents. Additionally, data related to gender showed significant differences between infected and control men and women. Considering age, reviewing the results of these studies revealed a significant difference between the infected people and the Toxoplasma-negative subjects under 45 years of age. However, no significant difference was found between the two groups aged 45 or older. Given these results, it can be concluded that Toxoplasma gondii significantly increases the risk of having traffic accidents.

Toxoplasmosis seroprevalence in rheumatoid arthritis patients: A systematic review and meta-analysis

BACKGROUND

Toxoplasmosis is a cosmopolitan infection caused by an intracellular obligatory protozoan, Toxoplasma gondii. Infection to this parasite in immunocompetent patients is usually asymptomatic, but today it is believed that the infection can be a risk factor for a variety of diseases, including rheumatoid arthritis (RA). RA is an autoimmune disease and the most common type of inflammatory arthritis that is a major cause of disability. The aim of this systematic review and meta-analysis was to address the association between RA and toxoplasmosis in light of the available research.

METHODS

Based on the keywords, a systematic search of eight databases was conducted to retrieve the relevant English-language articles. Then, the studies were screened based on the inclusion and exclusion criteria. The random effect model was used to calculate the odds ratio (OR) using forest plot with 95% confidence interval (CI).

RESULTS

Overall, 4168 Individual, extracted from 9 articles were included for systematic review evaluation, with 1369 RA patients (46% positive toxoplasmosis) and 2799 individuals as controls (21% positive toxoplasmosis). Then, eight articles (10 datasets) were used for meta-analysis (1244 rheumatoid arthritis patients and 2799 controls). By random effect model, the combined OR was 3.30 (95% CI: 2.05 to 5.30) with P < 0.0001.

CONCLUSION

Although toxoplasmosis could be considered as a potential risk factor for rheumatoid arthritis, more and better quality studies are needed to determine the effect of T. gondii infection on induction or exacerbation of RA. Our study was registered at the International Prospective Register of Systematic Reviews (PROSPERO; code: CRD42017069384).

A multiplex restriction enzyme-PCR for unequivocal identification and differentiation of Trichostrongylus species in human samples

Trichostrongylus species remain one of the major health challenges in the tropical and summer rainfall regions worldwide. Identification of strongylid species diagnostic methods is vital for obtaining a deep understanding of the epidemiology, population biology, anthelmintic treatment efficacy, and drug resistance in order to design effective parasite control strategies. We evaluated a multiplex RE-PCR for the diagnosis of key Trichostrongylus spp. Genomic DNA amplification of Trichostrongylus colubriformis, Trichostrongylus axei and Trichostrongylus vitrinus was achieved as standard sample using specific primers located in the second internal transcribed spacer (ITSII) of nuclear ribosomal DNA (rDNA). The mentioned method was based on isolation of Trichostrongylus ova from human fecal samples using Willis method, the extraction of ova genomic DNA samples, followed by rDNA ITSII PCR and one-step multiplex RE-PCR using three restriction enzymes of HinfI, DraI, and MseI. The multiplex RE-PCR technique provides a useful tool for discriminating all Trichostrongylus spp., being useful for diagnostic, epidemiological, ecological studies, and control programs. This method is rapid, especially when numerous restriction enzymes are required for species differentiation or identification.

Genetic diversity of Toxoplasma gondii isolates from ruminants: A systematic review

Toxoplasma gondii is a protozoan capable of infecting all warm-blooded animals. This parasite has been classified into three major lineages. Our aim was to assess and compare the identified Types and genotypes in ruminants. From November 2014 to April 2015, four English language databases and four Persian databases that reported data on the T. gondii genotyping in ruminants were searched. Overall, typing results of the 250/307 T. gondii isolates in all animals showed that Type II was a predominant Type (81.4%). In addition, genotyping data from the 82/215 T. gondii isolates or strains indicated that atypical genotypes were predominant (38.13%). This systematic review has demonstrated a large degree of genetic diversity in some countries. However, in the new nomenclature of genotyping, there are atypical or exotic genotypes, such as Chinese 1, Types Br (I, II, III and IV), and Type 12. Further genotyping studies are required to corroborate the current results.

Intestinal parasitic infections in Iranian preschool and school children: A systematic review and meta-analysis

Parasitic infections are a serious public health problem because they cause anemia, growth retardation, aggression, weight loss, and other physical and mental health problems, especially in children. Numerous studies have been performed on intestinal parasitic infections in Iranian preschool and school children. However, no study has gathered and analyzed this information systematically. The aim of this study was to provide summary estimates for the available data on intestinal parasitic infections in Iranian children. We searched 9 English and Persian databases, unpublished data, abstracts of scientific congresses during 1996-2015 using the terms intestinal parasite, Giardia, Cryptosporidium, Enterobiusvermicularis, oxyure, school, children, preschool, and Iran. We conducted meta-analysis using STATA, and for all statistical tests, p-value less than 0.05was considered significant. Among the 68,532 publications searched as a result, 103 were eligible for inclusion in the study. The prevalence rate of intestinal parasitic infections was 38% (95% CI- 33%, 43%). Prevalence of protozoa, helminthic intestinal infections, and non-pathogenic parasites was 16.9%, 9.48%, and 18.5%, respectively, which affected 14.27% males and 15.3% females. The rate of infection in preschool and school children was 38.19% and 43.37% respectively. Giardia, Enterobiusvermicularis and Entamoeba coli were the most common among protozoa, helminthic, and non-pathogenic infections (15.1%, 16.5%, and 7.1%, respectively). The data analyses indicated that the prevalence of intestinal parasitic infection is decreasing in Iranian preschool and school children. Improvement of sanitation, personal hygiene, increased awareness of people, seasonal variations, and health education can be effective in reducing parasitic infections in different communities.

Toxoplasmosis seroprevalence in Iranian women and risk factors of the disease: a systematic review and meta-analysis

BACKGROUND

Toxoplasmosis is caused by an intracellular obligatory parasite, Toxoplasma gondii, and it has global distribution. The purposes of this systematic review and meta-analysis were to evaluate the seroprevalence of toxoplasmosis in Iranian pregnant women, and girls and women of childbearing age, and identify potentially preventable risk factors.

METHODS

Between November 2014 and February 2017, nine electronic databases that reported data on the T. gondii seroprevalence in Iranian women were searched. Our search resulted in 83 reports published from 1994 to 2017.

RESULTS

The results showed that the pooled estimation for the prevalence of T. gondii using a random-effect model was 43% (95% confidence interval (CI) = 38-48%) in pregnant women and 33% (95% CI = 23-43%) in girls and the childbearing age groups. There was a significant association between the T. gondii seroprevalence with age and the gestational age of conception in pregnant women and those who had contact with cats in both groups.

CONCLUSIONS

This is the first comprehensive systematic review of T. gondii infection seroprevalence in Iranian women, which showed a high prevalence of Toxoplasma infection. Around 57% of pregnant women and 67% of girls and the childbearing age groups were seronegative and thus were susceptible to infection and should be monitored.

Seroepidemiological survey of helminthic parasites of stray dogs in Sari City, northern Iran

The objective of this study was to determine the prevalence rate of helminthic parasites in stray dogs' population especially zoonotic infections and to identify potential risk factors in the different areas of Sari city in Caspian area, north of Iran. During the period from April to September 2007, 50 stray dogs were collected from urban areas of Sari city. Recovered parasites were fixed in alcohol and stained by carmine then observed by microscope. The taxonomic study was carried out by measuring different parts of the body of helminthes and statistical tests were performed using the Chi-square test. A total of 27 adult and 23 juvenile stray dogs were collected and the overall prevalence rate of infection was 90%. The three most common helminthes were Toxocara canis (60%), Ancylostoma caninum (46%) and Dipylidium caninum (36%). Other parasites were Uncinaria stenocephala (12%), Taenia hydatigena (6%), Spirocerca lupi (6%), Dirofilaria immitis (6%), Toxascaris leonina (2%), Rictularia sp. (2%), Taenia ovis (2%) and Taenia taeniformis (2%). Five species of zoonotic helminthes recovered were T. canis, A. caninum, U. stenocephala, D. caninum and D. immitis. Hookworm infections (58%) were more common significantly in the young stray dogs (p < 0.01). In regard to prevalence ofA. caninum, T. canis and U. stenocephala, there was significant difference between juvenile and adult dogs (p < 0.05). The results highlight the potential role of stray dogs for transmission of helminthic parasites particularly zoonotic parasites that are a significant risk to human health.

Prevalence of Toxocara canis in stray dogs, northern Iran

Toxocara canis is one of the most common parasites living in the intestine of domestic and stray dogs. A dog eliminates thousands of eggs into the environment that are potential etiological factor for human toxocariasis. The present study was undertaken to determine the prevalence of T. canis in stray dogs in Mazandaran, Iran. In this cross-sectional study, during the period from April to September 2007, 50 young and adult stray dogs were collected by shooting from urban areas of Sari city, Northern Iran. They were necropsied and the gastrointestinal tract was opened. Recovered parasites were fixed in alcohol and stained in carmine. Faecal specimens were also examined by the formalin ether concentration method. A total of 27 adult and 23 young dogs were examined with 11 adults (40.7%) and 19 youngs (82.6%) being infected with T. canis with an overall prevalence of 60%. There were significant differences in the prevalence of infection between adult and young dogs (p = 0.003). There were no significant differences in the prevalence of infection between male and female dogs (p > 0.05). Considering the high prevalence of this zoonotic parasite and its hygienic significance in causing human toxocariasis, particularly in children, plus the lack of control of stray dog populations, there is a need to improve personal and food hygiene as well controlling stray dogs in these urban