Prevalence of Strongyloides stercoralis in the immunocompetent and immunocompromised individuals in Iran: a systematic review and meta-analysis.

Strongyloidiasis is a neglected tropical disease mostly distributed in tropical and subtropical regions. The current study evaluated the prevalence of Strongyloides stercoralis in immunocompetent and immunodeficient patients in Iran. The available online literature published from June 1994 to October 2020 was obtained from multiple English databases (PubMed, Science Direct, Scopus, Web of Science and Google Scholar) and four Persian databases (Magiran, Iran Medex, Iran Doc and SID). All statistical analyses were performed using R software (version 3.6) meta-package and p-values <0.05 were considered significant. From 1051 articles, 74 studies (248 656 individuals) met the inclusion criteria. The pooled prevalence of S. stercoralis was 2% (95% confidence interval [CI] 1 to 3) and 4% (95% CI 1 to 8) in immunocompetent and immunodeficient patients, respectively. In immunodeficient cases, the pooled prevalence of studies utilizing serology, culture and microscopic methods was 10% (95% CI 2 to 23), 1% (95% CI 0 to 6) and 1% (95% CI 0 to 1), respectively. In immunocompetent cases, the pooled prevalence of studies utilizing microscopic, culture and molecular methods was 2% (95% CI 1 to 3), 2% (95% CI 1 to 4) and 2% (95% CI 0 to 6), respectively. We propose an appropriate screening and control program along with comprehensive research regarding the frequency of strongyloidiasis in the country.

Global prevalence of Trichomonas vaginalis among female sex workers: a systematic review and meta-analysis.

Trichomoniasis is a sexually transmitted infection (STI), caused by the protozoan parasite, Trichomonas vaginalis. Female sex workers are intensely affected by the infection, since they have frequent direct physical contact. The current systematic review and meta-analysis represents the global prevalence of T. vaginalis in female sex workers. Five databases (Science Direct, Scopus, PubMed, Web of Science, and Google Scholar) were explored for literatures that published from July 1985 to June 2020. Totally, 85 studies (54,515 participants) from 46 countries met the inclusion criteria. The global pooled prevalence of T. vaginalis was 16% (95% CI 13-19%). The estimated pooled prevalence based on methods including wet mount, culture, and molecular techniques was 15% (95% CI 12-19%), 16% (95% CI 10-24%), and 22% (95% CI 13-32%), respectively. Moreover, the infection was most prevalent at the mean age of 30-36 (20%, 95% CI 11-30%). Regarding the World Health Organization (WHO) regions, the highest pooled prevalence was estimated to be in the African region (23%, 95% CI 7-46%). In addition, we indicated that countries with low-income level have the highest pooled prevalence (23%, 95% CI 14-34%). Our results revealed that the worldwide prevalence of T. vaginalis was significant in female sex workers. Therefore, considering a precise strategy such as a health education program with regard to safe intercourse is needed to increase knowledge and prevent T. vaginalis infection in sex workers.

Occurrence of Dioctophyme renale (Goeze, 1782) in road-killed canids of Iran and its public health implication.

Dioctophyme renale, is the largest of parasitic nematodes, which infects different species of fish-eating carnivores worldwide. The northern provinces of Iran (Guilan and Mazandaran) located in south of the Caspian Sea are suitable for parasitic infections due to the mild and humid climatic conditions. From separate surveys of road-killed canids in various parts of the Caspian Sea littoral area in Iran, 70 carcasses were collected along the roads of Guilan and Mazandaran from 2015 to 2017. Dioctophyme renale detected by direct observation and molecular methods based on Cytochrome c oxidase subunit 1 (COX1 gene) sequencing analysis. Molecular investigation was also performed to validate prevalence and reduce false negative concerns. Dioctophyme renale was found in eight of 70 carnivores, mostly in the right kidneys, as well as two cases in the abdominal cavity of a dog and a golden jackal. More carcasses on the roads were seen with lacerated internal organs. Given the frequent number of giant kidney worms in canids in the region, the transmission of this zoonotic helminth to humans seems possible, since the area is a tourism hub in the country. The infection burden of this helminth should be investigated using DNA analysis of kidney tissue of road-killed carnivores in Iran.

Current Global Status and the Epidemiology of Entamoeba gingivalis in Humans: A Systematic Review and Meta-analysis.

PURPOSE: Entamoeba gingivalis (E. gingivalis) is one of the members of the wide range of oral resident pathogens in humans, particularly found in dental plaques, surfaces of gingiva or teeth, interdental spaces and carious lesions. The purpose of the current review and meta-analysis was to determine the global prevalence of E. gingivalis infection and its association with oral diseases based on published literatures. MATERIALS AND METHODS: Multiple English databases (PubMed, Scopus, Science Direct, Web of Science and Google Scholar) were explored for papers published until August 2020. A total of 52 studies (including 7596 participants) met the inclusion criteria. RESULTS: The overall prevalence of E. gingivalis was estimated to be 37% (95% CI 29-46%). With regard to different countries, the highest and lowest pooled prevalence of E. gingivalis infection were related to Jordan with 87% (95% CI 81-92%) and Portugal with 3% (95% CI 0-10%), respectively. Based on WHO regions, the highest prevalence was related to the region of the Americas with 56% (95% CI 31-79%). The infection was most prevalent in 46-55 mean age groups [61% (95% CI 21-94%)]. Among different diagnostic methods, the highest rate of the pooled prevalence was related to the molecular [53% (95% CI 24-81%)] and the direct methods [36% (95% CI 25-47%)], respectively. Our analyses revealed that E. gingivalis infection was associated with 4.34-fold increased risk of oral diseases (P < 0.05). CONCLUSION: Our findings revealed a high prevalence rate of the infection among periodontal disease patients with 37% (95% CI 20-57%). To conclude, it must be considered that E. gingivalis can be a risk factor associated with oral diseases and a wide range of research is needed to specify its role in the pathogenesis of these disorders.

Keys to Unlock the Enigma of Ocular Toxocariasis: A Systematic Review and Meta-analysis.

PURPOSE: Ocular toxocariasis (OT) is a zoonotic infection caused by larval stages of Toxocara canis and T. cati. The current review and meta-analysis aimed to evaluate the global prevalence of OT. METHODS: Five English (PubMed, Scopus, Science Direct, Web of Science, and Google Scholar) databases were explored and 101 articles met the inclusion criteria. RESULTS: The pooled prevalence (95% confidence interval) of OT was higher in immunological studies (9%. 6-12%) than in studies that applied ophthalmic examination (1%. 1-2%). The lower middle-income level countries had the highest prevalence (6%. 2-12%) as well as the African region (10%. 7-13%). The highest infection rate (4%. 2-7%) was detected in the 1-25 mean age group. CONCLUSION: Regular anthelminthic treatment of cats and dogs, and removal of animal feces from public places must be considered.

The Neglected Role of Trichomonas tenax in Oral Diseases: A Systematic Review and Meta-analysis.

PURPOSE: Trichomonas tenax (T. tenax) is a commensal flagellated protozoan found in periodontal microenvironment of the oral cavity, with a possible role in periodontal diseases. The purpose of the present systematic review and meta-analysis was to determine the worldwide prevalence of T. tenax infection and to show the neglected association of this parasitic infection with oral diseases. METHODS: To find literatures published until August 2020, five English databases (PubMed, Scopus, Science Direct, Web of Science and Google Scholar) were explored. Finally, 65 papers were qualified to be included in the current study. RESULTS: Our results revealed a global pooled prevalence of 17% (95% CI 14-22%) for T. tenax infection. The highest prevalence was estimated at 56% (42-69%) in Chile, while the lowest prevalence was related to Kenya with 3% (1-6%). The age-based analysis found that the infection was most common in 46-55 mean age group with 15% (0-100%). The overall prevalence regarding culture method, molecular method and direct method was 21% (12-32%), 19% (8-35%) and 17% (12-23%), respectively. Moreover, the subgroup analysis showed the pooled prevalence in patient with candidiasis [22% (3-52%)], gingivitis [21% (9-36%)] and periodontitis [27% (10-48%)]. CONCLUSION: Our study specified a connection between T. tenax protozoa and periodontitis disease. However, more epidemiological studies as well as clinical trials are needed to precisely identify this relation.

Prevalence of strongyloidiasis in the general population of the world: a systematic review and meta-analysis.

Strongyloides stercoralis is a neglected soil-transmitted helminth affects approximately 100-370 million people globally. The life cycle is unusual as only larvae can be found in stool specimens. Thecurrent review and meta-analysis represented the distribution of strongyloidiasis in general population of the world based on published papers. Five English databases (Science Direct, Scopus, PubMed, Web of Science, and Google Scholar(were explored for literature published before October 2019.Altogether 235 studies (862243 participants) was eligible. Regarding diagnostic method, the overall prevalence for studies performed microscopic, culture, immunological and molecular method was 1.47% (95% CI = 1.56%), 10.08% (95% CI = 8.99% - 11.16%), 23.88% (95% CI =  20.82% - 26.94%) and 9.3% (95% CI  =  7.2% - 11.3%), respectively. Based on microscopic methods, the highest prevalence was related to the Western Pacific region [9.47% (95% CI =  8.55% - 10.39%)]. According to the culture method, Western Pacific region [21.36% (95% CI  =  16.32% - 26.39%)] had the highest estimated pooled prevalence. In immunological studies, Eastern Mediterranean Region [40.72% (95% CI  =  36.74% - 44.70%)] had the highest seroprevalence.Also in molecular surveys, the highest prevalence was related to the African region [19.72% (95% CI  =  16.71% - 22.73%)]. The current study indicated that strongyloidiasis is still considered a health problem in many parts of the world. Thus a comprehensive control program and improvement of public health sectors are required.

Molecular and Morphological Data Confirmed First Record of Abbreviata kazakhstanica Markov and Paraskiv, 1956 (Spirurida: Physalopteridea) in Iran.

BACKGROUND: The genus Abbreviata (Spirurida: Physalopteridea) currently contains 47 species. Physalopteridae nematodes infect a large number of vertebrates, including mammals, birds, reptiles and amphibians. The current study is a report of the first morphological and molecular identification of A. kazakhstanica (Spirurida: Physalopteridea) in Pseudopus apodus in Iran. METHODS: Eleven road-killed P. apodus, were collected from, Iran during 2016-2018. The nematodes were isolated from stomach. After morphological study, the genomic DNA of the parasites was extracted using CTAB method. The DNA was used for PCR amplification of cytochrome c oxidase subunit I (cox1). The PCR products were sequenced, the sequence data were analyzed and multiple alignments were conducted using the Clustal Omega. RESULTS: After detailed microscopic examination, the A. kazakhstanica was identified. The cox1 sequences confirmed the species of helminth. The new sequences of A. kazakhstanica were submitted to GenBank under the accession number MK578751-2. CONCLUSION: Regarding the limited data on parasitological status of Iranian reptiles, more specific and comprehensive investigations are needed to identify the parasitic fauna.

Molecular Characterization of Echinococcus granulosus Sensu Stricto Isolated from the Livestock of Qazvin, Iran.

INTRODUCTION: Hydatidiosis is a serious parasitic disease in humans and livestock, worldwide. Echinococcus granulosus shows notable genetic variation among intermediate hosts. Several genotypes of the worm have been reported from different parts of Iran, but no information on the parasite genotypes status in the study region is available. The current study investigated the presence of different genotypes of E. granulosus in the livestock of Qazvin, Iran, by sequencing the mitochondrial Cox1 genes. METHODOLOGY: One hundred twenty E. granulosus isolates, including 30 from goats, 40 from cattle and 50 from sheep, were collected from the slaughterhouses in Qazvin province. Mitochondrial Cox1 gene region was amplified by PCR and 30 isolates were sequenced. Phylogenetic analysis was performed by using the MEGA 7.0 software. Morphological analysis was performed on rostellar hook length of protoscoleces. RESULTS: All isolates were identified as E. granulosus sensu stricto (G1-G3 complex) among 17% of the isolates clarified as G3 genotypes. G1 was the predominant genotype among the specimens. No significant difference between the rostellar hooks measurements of different genotypes was observed. CONCLUSION: Our findings confirmed the presence of E. granulosus sensu stricto in the region, although further studies are required to determine the haplotype diversity of E. granulosus using different mitochondrial and nuclear genes.