ABSTRACT
Toxoplasma gondii (T. gondii) as an obligate intracellular protozoan with a worldwide distribution can infect virtually all warm-blooded animals and humans. This study aims to provide a summary of the available data on genotypes of T. gondii in human. Five databases including MEDLINE in PubMed, Scopus, Science Direct, Web of Science and Google Scholar were searched for the T. gondii genotyping in human during 1995-August 2017. Next, we screened all the articles based on the inclusion and exclusion criteria. Overall, 26 studies were eligible regarding genotyping T. gondii in human samples. In clonal genotyping, 167 out of 286 cases (58%) were infected with type II. Genetic characterisation of T. gondii isolates displayed that type II was the most predominant genotype in human with the prevalence of 64.3%, 62.1% and 41.7% in patients with AIDS, congenital and ocular toxoplasmosis, respectively. In ToxoDB genotyping, most individuals were infected with genotypes #9 and #65 (21.2%). Based on these results, genotype profile of T. gondii isolates is different throughout the world. The strains in Asian and African countries are characterised by low genetic diversity, while in North and South America a wide diversity of this parasite is found. In countries without any data (e.g. Australia, Western and Southern Africa and Western Asia), identification of T. gondii genotypes might discover higher genetic diversity.
ABSTRACT
Toxoplasmosis, a cosmopolitan parasitic infection caused by Toxoplasma gondii, is frequently found in meat-producing animals and human beings. This review and meta-analysis study was performed to evaluate the overall prevalence of T. gondii infection among sheep and goats in Iran. Data were systematically collected from 1977 to 2012 in Iran on the following electronic databases: PubMed, Google Scholar, Science Direct, Scopus, Web of Science, Magiran, Irandoc, IranMedex, and Scientific Information Database (SID). Additionally, abstracts of national scientific congresses and dissertations were included. A total of 34 articles in field of sheep and 18 articles about goat toxoplasmosis, totalizing to the examination of 14,372 sheep and 3,120 goats, reporting prevalence of toxoplasmosis from different regions of Iran fulfilled our eligibility criteria. The overall prevalence rate of toxoplasmosis in Iran was estimated to be 31% (95% confidence interval (CI) = 0.259825 to 0.352382) in sheep and 27% (95% CI = 0.140097 to 0.424782) in goats, respectively. There was no significant difference in infection rate between males and females among sheep (odds ratio (OR) = 1.002, 95% CI = 0.59 to 1.696) and goats (OR = 1.027, 95% CI = 0.685 to 1.541). Analysis revealed that infection rate in sheep over than 1 year old was 2.4 times more than that in less than 1 year old (OR = 2.396, 95% CI = 1.050 to 5.467). This systematic review and meta-analysis study revealed that infection is widespread in Iran. Further studies are required to improve strategies for controlling infection among flocks and consequently in human population.
