Toxoplasmosis snapshots: Global status of Toxoplasma gondii seroprevalence and implications for pregnancy and congenital toxoplasmosis

SUMMARY Infections by the protozoan parasiteToxoplasma gondiiarewidely 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 Governmentprovidesauniqueopportunityforinternationalgroupstostudytheepidemiologyandcontroloftoxoplasmosis 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 10000 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 childrenwhoseclinicaldataaredescribedinthisreview,severaldiedsoonafterbirth,35%hadneurologicaldiseaseincluding 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

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

Prenatal management of 746 pregnancies at risk for congenital toxoplasmosis

PURPOSE: to establish the frequency of acute toxoplasmosis in pregnant women, vertical transmission rate and the perinatal results of the infected fetuses and also to evaluate the relationship between the most used maternal-fetal diagnostic tests for toxoplasmosis during pregnancy and the relationship between age and acute toxoplasmosis infection during pregnancy. METHODS: longitudinal prospective study of 32,512 pregnant women attended by The Pregnancy Protection Program of the State of Mato Grosso do Sul - Brazil, from November 2002 to October 2003. ELISA (IgG and IgM) and IgG avidity test were performed for maternal diagnosis and amniotic fluid PCR for fetal investigation of the infection. The relationship between data was analyzed statistically by the c2 or two-sided Fisher's exact test in contingency tables. RESULTS: a 0.42% frequency of acute Toxoplasma gondii infection among pregnant population was found, where 92% were previously exposed and 8% were susceptible. Among IgM-positive pregnant women, the age ranged from 14 to 39 years, with a mean of 23±5.9 years. There was no statistically significant relationship between age and maternal acute T. gondii infection (p=0.73). The vertical transmission rate was 3.9%. A statistically significant relationship was shown (p=0.001) between a lower avidity IgG test ( 60%) and the absence of fetal infection. There was a statistically significant association (p=0.001) between fetal infection (amniotic fluid PCR) and neonatal infection. CONCLUSIONS: maternal acute toxoplasmosis frequency was lower than the Brazilian national parameters, whereas vertical transmission rate did not differ from the rates found in other studies. The IgG avidity test, when associated with gestational age and the examination date, was useful to evaluate the therapeutical options and to consider the risk of vertical transmission when performed before 12 weeks. Positive PCR in amniotic fluid showed a positive relationship with the worst neonatal prognosis, being a specific method in diagnosing intrauterine fetal infection.

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Toxoplasmose aguda: estudo da freqüência, taxa de transmissão vertical e relação entre os testes diagnósticos materno-fetais em gestantes em estado da Região Centro-Oeste do Brasil

To determine the prevalence of immunoglobulin G (IgG) and immunoglobulin M (IgM) anti-Toxoplasma gondii antibodies among pregnant and postpartum women attended within the public healthcare system in Niteroi, State of Rio de Janeiro,and to detect possible exposure factors associated with T. gondii infection in this population.

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Prevalence and risk factors for Toxoplasma gondii infection among pregnant and postpartum women attended at public healthcare facilities in the City of Niterói, State of Rio de Janeiro, Brazil

OBJECTIVE: to establish the rate of toxoplasmosis soroprevalence in postpartum women, attended in two hospitals of the Public Health System (SUS) in Cuiaba, and its correlation with age, previous abortion and women's knowledge of the disease. METHODS: a cross-sectional study including 205 women with ages from 14 to 43 (mean 22.4) years old, attended in these hospitals for two months, in the first or second days postpartum. Each woman answered a short questionnaire and had peripheral blood sample collected. Blood samples were stored at 20°C until assay. The seroprevalence was determined by quantitative detection of specific IgG antibody against Toxoplasma gondii, using a microparticle enzyme immunoassay. All samples were assayed at the same time. RESULTS: The average number of pregnancies in the women included in this study was 2.2, and the majority of them was pregnant for the first time. The seroprevalence found was 70.7% (165 of 205 women). No statistical correlation was found between seroprevalence and age (p = 0.967) or previous abortion (p = 0.82). Most of the women in this study (78%) did not know about toxoplasmosis and no statistical correlation was found between this condition and seroprevalence (p = 0.49). CONCLUSION: the high seroprevalence found in the present study is in accordance with surveys previously reported in our country and other developing countries. Among the women included in this study, an expressive number (29.3%) is still under risk of contamination. The lack of statistical correlation between seroprevalence and women's age, lack of knowledge about the disease and report of previous abortion is in accordance with some previous studies and in disagreement with others.

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Toxoplasmose: soroprevalência em puérperas atendidas pelo Sistema Único de Saúde

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Paulo Roberto Dutra Leão

Papers

Toxoplasmose: soroprevalência em puérperas atendidas pelo Sistema Único de Saúde

Toxoplasmose: Soroprevalência em Puérperas Atendidas pelo SUS em Cuiabá, Mato Grosso