Incidence of congenital toxoplasmosis in southern Brazil: a prospective study

Abstract

SUMMARYThe study aimed to determine the incidence of congenital infection by Toxoplasma gondii and to describe neonatal and maternal characteristics regarding newborn infants treated at a teaching hospital in the town of Passo Fundo, State of Rio Grande do Sul, Brazil. Cord blood samples collected from 1,250 live newborns were analyzed. The laboratory diagnosis was established by the detection of Toxoplasma gondii IgM using an enzyme linked fluorescent assay. Gestational age, intrauterine growth, anthropometric measures, and prenatal characteristics were assessed. The incidence of congenital toxoplasmosis at birth was 8/10,000 (95%CI 0.2-44.5). Mean birthweight was 3,080 ± 215.56 grams and mean gestational age was 38.43 ± 1.88 weeks. With regard to prenatal care, 58% of the pregnant patients visited their doctors five times or more and 38.9% were serologically tested for toxoplasmosis in the first trimester of pregnancy. The incidence of congenital toxoplasmosis was similar to that found in most studies conducted in our country and abroad. Our study sample is representative of the town of Passo Fundo and therefore it is possible to consider the frequency observed as the prevalence of the disease in this town during the study period.

Prevalence of acute toxoplasmosis infection among 41,112 pregnant women and the mother-to-child transmission rate in a public hospital in South Brazil

“…The prevalence of CTox by the end of the first year of life in our study (0.9/1,000 newborns) was comparable to that found at birth in other areas of Southern Brazil (Glasner et al 1992, Mozzatto & Procianoy 2003, Lago et al 2007. A prevalence of 5.0/1,000 newborns reported in Minas Gerais, Brazil, could partially be explained by the use of cord blood samples (Segundo et al 2004).…”

“…In the Southern region, the prevalence of congenital infection based on cord blood samples reached 0.8/1,000 births (95% CI: 0.02-4.45) (Mozzatto & Procianoy 2003). Other studies using blood samples adsorbed onto filter paper found prevalences from 0.3/1,000 (Neto et al 2000) to 0.6/1,000 newborns (Lago et al 2007).…”

Ocular manifestations of congenital toxoplasmosis

“…Previous studies show that this region has a high prevalence of ocular acquired toxoplasmosis, and concomitantly, the rate of congenital toxoplasmosis currently can be considered as one of the highest in the world. [2][3][4]32,33 It has been widely accepted that approximately 90% of newborns with a serological diagnosis of congenital toxoplasmosis have a normal physical examination at birth and only about 40% present ocular and/or neurological alterations after further investigation. 6,15,18 This study definitely showed that ocular involvement may be more frequent and occurs earlier than previously described.…”

“…In recent studies conducted in Rio Grande do Sul, Brazil, a high incidence of congenital toxoplasmosis was shown, ranging from 6 to 8 per 10 000 live births. [2][3][4] Vertical transmission of toxoplasmosis occurs during primary infection in pregnant women, and generally the maternal disease goes unnoticed. When pregnant women become infected in the first trimester, the frequency of fetal infection goes up to 15-20%, in the second up to 25%, and in the third up to 65-70%.…”

Diagnóstico molecular da toxoplasmose: revisão

“…Os casos de reativação da infecção pelo T. gondii, causados por imunossupressão materna, poderiam levar à infecção do feto durante a gravidez (52) . O sucesso da infecção fetal depende de fatores como virulência do T. gondii, desenvolvimento placentário, idade gestacional e carga parasitária, entre outros (1) .…”