Evidência sorológica da infecção aguda pelo Toxoplasma gondii em gestantes de Cascavel, Paraná

Risk factors associated with toxoplasmosis and toxocariasis in populations of children from nine cities in southern Brazil

This study investigated the epidemiological factors that contribute to the seroprevalence of Toxoplasma gondii and Toxocara spp. in children from Paraná state, Brazil. Immunoglobulin G (IgG) antibodies to T. gondii were detected using indirect immunofluorescence, and IgG antibodies to Toxocara were detected using an enzyme-linked immunosorbent assay. For each individual, a questionnaire was completed that contained epidemiological and clinical data. The data analysis was performed using multiple logistic regression. Of the 544 children investigated, 3.2% presented co-infection with T. gondii and Toxocara spp. Of this total, 7.4% were positive for antibodies to T. gondii, and 25% were positive for antibodies to Toxocara spp. The presence of antibodies to Toxocara spp. increased the risk of T. gondii infection (P = 0.029). Children who were 1-8 years of age were less infected by T. gondii than those who were 9-12 years of age. The variables that influenced positivity for anti-Toxocara spp. were the origin of the children and contact with sand. Children with positive serology for Toxocara spp. presented more eosinophilia compared with those with non-reactive serology. Infection with both parasites reveals the need for preventive measures, such as guidance about modes of infection, parasite control and monitoring recreational areas.

Toxoplasmosis in humans and animals in Brazil: high prevalence, high burden of disease, and epidemiology

Infections by the protozoan parasite Toxoplasma gondii are widely prevalent in humans and animals in Brazil. The burden of clinical toxoplasmosis in humans is considered to be very high. The high prevalence and encouragement of the Brazilian Government provides a unique opportunity for international groups to study the epidemiology and control of toxoplasmosis in Brazil. Many early papers on toxoplasmosis in Brazil were published in Portuguese and often not available to scientists in English-speaking countries. In the present paper we review prevalence, clinical spectrum, molecular epidemiology, and control of T. gondii in humans and animals in Brazil. This knowledge should be useful to biologists, public health workers, veterinarians, and physicians. Brazil has a very high rate of T. gondii infection in humans. Up to 50% of elementary school children and 50-80% of women of child-bearing age have antibodies to T. gondii. The risks for uninfected women to acquire toxoplasmosis during pregnancy and fetal transmission are high because the environment is highly contaminated with oocysts. The burden of toxoplasmosis in congenitally infected children is also very high. From limited data on screening of infants for T. gondii IgM at birth, 5-23 children are born infected per 10 000 live births in Brazil. Based on an estimate of 1 infected child per 1000 births, 2649 children with congenital toxoplasmosis are likely to be born annually in Brazil. Most of these infected children are likely to develop symptoms or signs of clinical toxoplasmosis. Among the congenitally infected children whose clinical data are described in this review, several died soon after birth, 35% had neurological disease including hydrocephalus, microcephaly and mental retardation, 80% had ocular lesions, and in one report 40% of children had hearing loss. The severity of clinical toxoplasmosis in Brazilian children may be associated with the genetic characteristics of T. gondii isolates prevailing in animals and humans in Brazil.

Preventive behavior for toxoplasmosis in pregnant adolescents in the state of Ceara, Brazil

BACKGROUND

When toxoplasmosis is acquired during pregnancy, it can be transmitted to the fetus causing severe lesions in the first two gestational trimesters. This study analyzed the main factors associated with the preventive behavior for toxoplasmosis among pregnant adolescents in the city of Fortaleza in northeast Brazil.

METHODS

It is a cross-sectional study conducted from March 2009 to November 2010, with a sample of 320 pregnant adolescents, ages ranging from 12 to 19 years old, receiving prenatal care in the Public Health Care System. Bivariate and multivariate logistic regression model analyses were used to identify the association between preventive behavior for toxoplasmosis, and the independent variables and 95% confidence interval.

RESULTS

We observed that 16.3% of the pregnant adolescents showed preventive behavior for toxoplasmosis. The factors positively associated to the preventive behavior for toxoplasmosis were: age group between 12 and 14 years old (OR = 2.75; 95%CI 1.23-6.12) and more than two prenatal consultations (OR = 2.19; 95%CI 1.17-4.09).

CONCLUSIONS

Noteworthy is the importance of a serologic follow-up for pregnant adolescents with clearer and more precise information about risk factors and the importance of adopting preventive behaviors. Thus, it is necessary to establish educational measures for handling food and raising kittens during prenatal care.

Serological prevalence of Toxoplasma gondii antibodies in pregnant women from Southern Brazil

During 15 months (01 April 2003-31 July 2004), 20,389 women showing positive pregnancy tests were included in a serological evaluation of toxoplasmosis prevalence using automated immunoenzymatic assays. The women's serum samples were tested for the presence of IgG and/or IgM antibodies. Overall, 53.03% of the women were positive for IgG and 3.26% were positive for IgM; the analysis used a chi-square adherence test and a significance level of 0.05 (chi(2)=14,720.35; p=0.00). To discriminate between recent and past infection, IgG avidity tests (n=166) were carried out, of which 28.3% (n=47) presented low avidity. The seroconversion index observed in this study was 0.44%. The seroprevalence results obtained were similar to other serology data found in other regions of Brazil. These data demonstrate the importance of continuous regional and national seroepidemiological inquiries to define public health strategies that can revert and reduce serological prevalence, as described in other countries where toxoplasmosis monitoring is mandatory.