Seroprevalence of Toxoplasma gondii in the Iranian pregnant women: A systematic review and meta-analysis.

Toxoplasmosis is a common and serious parasitic disease with high prevalence and global distribution in human and other warm-blooded vertebrates. Though the infection of Toxoplasma gondii is usually asymptomatic in healthy people, it can lead to severe pathological effects to the fetus of infected women and immunocompromised patients. So pinpointing the risk factors and control procedures are of important works among these populations. In order to reach this goal, we conducted a systematic review and meta-analysis to identify the seroprevalence rate of T. gondii infection among Iranian pregnant women population to achieve a comprehensive explanation of the disease condition in Iran for future use. English electronic databases (PubMed, Science Direct, Scopus, Ovid and Cochrane) and Persian language databases (Scientific Information Database, Iran Medex, Magiran and Iran Doc) were searched. Furthermore, the proceedings of Iranian parasitology congresses were explored manually. Our review resulted in a total of 50 publications meeting the inclusion criteria during Jan 1990-June 2015. Totally, 20221 women had been tested during this period of which 7724 women had seropositivity for IgG. According to results of heterogeneity test, either Der Simonian and Laird's random-effects method or Mantel-Haenszel's fixed-effects method were used to pool the estimations. Weighted overall prevalence of toxoplasmosis in pregnant women were obtained using random-effects model, which was estimated 41% (95% CI=36-45%). Also IgG and IgM antibodies was obtained 38% (95% CI=34-42%) and 4% (95% CI=3-5%), respectively. The highest and the lowest seroprevalence of toxoplasmosis in five geographical zones of Iran were observed in South 53% (95% CI=30-77%) and East 33% (95% CI=23-42%), respectively. In order to detect publication bias, Egger's regression test was done which revealed that publication bias might not have a significant influence on overall prevalence estimate (P=0.89). Multivariate analysis showed that there's a statistically significant correlation between toxoplasmosis and two risk factors including "place of residence" (P=0.005) and "contact with cat" (P=0.002). There was no significant difference between toxoplasmosis and the other surveyed risk factors. It is highly recommended to further study for the aim of better disease management and developing more efficient diagnostic tests.