BackgroundToxoplasmosis is a disease caused by Toxoplasma gondii and at least one-third of the world’s population has detectable T. gondii antibodies. The seroprevalence of T.gondii ranges from 15% to 50% among the Mexican general population. The aim of this work was to determine the mean prevalence and weighted mean prevalence of T. gondii infection, and to evaluate the epidemiological transition of infection in Mexico.MethodsPub Med, Lilacs, Medline, Latindex, Google Scholar data bases were searched to retrieve reports from 1951 up to 2012 regarding prevalence data, diagnostic tests and risk factors of infection among the adult population. Data collection and criteria eligibility was established in order to determine the crude prevalence (proportion of positive cases) of each study, together with weighted population prevalence according to individual research group categories to limit the bias that may impose the heterogeneous nature of the reports. A Forest Plot chart and linear regression analysis were performed by plotting the prevalence of infection reported from each study over a period of sixty years.ResultsA total of 132 studies were collected from 41 publications that included 70,123 individuals. The average mean prevalence was 27.97%, and weighted mean prevalence was 19.27%. Comparisons among different risk groups showed that the weighted prevalence was higher in women with miscarriages (36.03%), immunocompromised patients (28.54%), mentally-ill patients (38.52%) and other risk groups (35.13%). Toxoplasma infection among the Mexican population showed a downward trend of 0.1%/year over a period of sixty years that represents a 5.8% reduction in prevalence.ConclusionsThis analysis showed a downward trend of infection; however, there are individuals at high risk for infection such as immunocompromised patients, mentally-ill patients and pregnant women. Further research is required to provide better prevention strategies, effective diagnostic testing and medical management of patients. Educational efforts are required to avoid the transmission of infection in populations that cannot be controlled by drugs alone.

Despite the limitations such as low number of studies, this meta-analysis suggests chronic toxoplasmosis as a possible risk factor for type 2 DM. However, based on random effects model no statistically significant association was observed between T. gondii and type 1 DM. It is highly recommended for researchers to carry out more accurate studies aiming to better understand this association.

A 7-year-old Mexican boy with end-stage cirrhosis underwent liver transplantation and was maintained with cyclosporine and prednisolone. No specific data about Toxoplasma gondii or cytomegalovirus (CMV) infections in the cadaver donor were available. The recipient was seronegative for Toxoplasma, but CMV-IgG positive before transplantation. Ganciclovir was administered for prophylaxis during 3 months, but 5 months later he presented with icterus and increased transaminases. Acute transplant rejection was ruled out by biopsy. A seroconversion for T. gondii IgM and IgG and a small increase in CMV-IgM antibodies were observed, although the CMV-polymerase chain reaction (PCR) was negative. Ganciclovir was re-started, and the patient improved, but 6 months later he relapsed, and chorioretinitis lesions compatible both with T. gondii and CMV infections appeared. Pyrimethamine, sulfadiazine, folinic acid, and ganciclovir were administered. The boy showed favorable clinical improvement and remained stable for 12 months. Then, new retinal CMV lesions appeared in both eyes and the PCR for CMV became positive; therefore, the patient received a new regimen of ganciclovir, and clinically improved. From these data we concluded that the child presented a reactivation of CMV and a primary infection with T. gondii after transplantation.

Background: Toxoplasma gondii is the causal agent of toxoplasmosis in which one third of the world's population has been infected. In pregnant women, it may cause abortion and severe damage to the fetal central nervous system. During pregnancy, the prevalence of toxoplasmosis increases throughout the second and third quarter of gestation, simultaneously progesterone and 17β-estradiol also increase. Thus, it has been suggested that these hormones can aggravate or reduce parasite reproduction. The aim of this study was reviewing the relationship between hormones and infection caused by T. gondii in several experimental animal models and humans, focused mainly on: (a) congenital transmission, (b) parasite reproduction, (c) strain virulence, (d) levels of hormone in host induced by T. gondii infection, and (e) participation of hormone receptors in T. gondii infection. Are the hormones specific modulators of T. gondii infection? A systematic review methodology was used to consult several databases (Pub Med, Lilacs, Medline, Science direct, Scielo, Ebsco, Sprinker, Wiley, and Google Scholar) dated from September, 2013 to March, 2014.Results: Thirty studies were included; eight studies in humans and 22 in animals and cell cultures. In the human studies, the most studied hormones were testosterone, progesterone, prolactin, and 17β-estradiol. Type I (RH and BK) and Type II (Prugniaud, SC, ME49, T45, P78, and T38) were the most frequent experimental strains.Conclusions: Thirty-five years have passed since the first studies regarding T. gondii infection and its relationship with hormones. This systematic review suggests that hormones modulate T. gondii infection in different animal models. However, given that data were not comparable, further studies are required to determine the mechanism of hormone action in the T. gondii infectious process.

BackgroundThe prevalence of toxoplasmosis in the general population of Guadalajara, Mexico, is around 32%. Toxoplasmosis can cause ocular lesions and slowing of reaction reflexes. Latent toxoplasmosis has been related with traffic accidents. We aimed to assess the prevalence of anti-Toxoplasma gondii antibodies and visual impairments related with traffic accidents in drivers from the metropolitan Guadalajara.MethodsWe prospectively evaluated the prevalence of IgG and IgM anti-T. gondii antibodies in 159 individuals involved in traffic accidents, and in 164 control drivers never involved in accidents. Cases of toxoplasmosis reactivation or acute infection were detected by PCR in a subset of 71 drivers studied for the presence of T. gondii DNA in blood samples. Ophthalmologic examinations were performed in drivers with IgG anti-T. gondii antibodies in search of ocular toxoplasmosis.ResultsFifty-four (34%) traffic accident drivers and 59 (36%) controls were positive to IgG anti-T. gondii antibodies (p = 0.70). Among the 113 seropositive participants, mean anti-T. gondii IgG antibodies titers were higher in traffic accident drivers than in controls (237.9 ± 308.5 IU/ml vs. 122.9 ± 112.7 IU/ml, respectively; p = 0.01 by Student’s t test, p = 0.037 by Mann–Whitney U test). In multivariate analyses, anti-T. gondii IgG antibody titers were consistently associated with an increased risk of traffic accidents, whereas age showed an inverse association. The presence of IgM-anti-T. gondii antibodies was found in three (1.9%) subjects among traffic accident drives, and in two (1.2%) controls. Three (4.2%) samples were positive for the presence of T. gondii DNA, all among seropositive individuals. No signs of ocular toxoplasmosis were found in the entire cohort. Moreover, no other ocular conditions were found to be associated with the risk of traffic accidents in a multivariate analysis.ConclusionsAnti-T. gondii antibody titers are associated with the risk of traffic accidents. We could not determine any association of ocular toxoplasmosis with traffic accidents. Our results warrant further analyses in order to clarify the link between toxoplasmosis and traffic accidents.