Ocular Sequelae of Congenital Toxoplasmosis in Brazil Compared with Europe

Abstract

BackgroundToxoplasmic retinochoroiditis appears to be more severe in Brazil, where it is a leading cause of blindness, than in Europe, but direct comparisons are lacking. Evidence is accumulating that more virulent genotypes of Toxoplasma gondii predominate in South America.MethodsWe compared prospective cohorts of children with congenital toxoplasmosis identified by universal neonatal screening in Brazil and neonatal or prenatal screening in Europe between 1992 and 2003, using the same protocol in both continents.ResultsThree hundred and eleven (311) children had congenital toxoplasmosis: 30 in Brazil and 281 in Europe, where 71 were identified by neonatal screening. Median follow up was 4.1 years in Europe and 3.7 years in Brazil. Relatively more children had retinochoroiditis during the first year in Brazil than in Europe (15/30; 50% versus 29/281; 10%) and the risk of lesions by 4 years of age was much higher: the hazard ratio for Brazil versus Europe was 5.36 (95%CI: 3.17, 9.08). Children in Brazil had larger lesions, which were more likely to be multiple and to affect the posterior pole (p<0.0001). In Brazil, visual impairment (<6/12 Snellen) was predicted for most affected eyes (87%, 27/31), but not in Europe (29%; 20/69, p<0.0001). The size of newly detected lesions decreased with age (p = 0.0007).Conclusions T. gondii causes more severe ocular disease in congenitally infected children in Brazil compared with Europe. The marked differences in the frequency, size and multiplicity of retinochoroidal lesions may be due to infection with more virulent genotypes of the parasite that predominate in Brazil but are rarely found in Europe.

Seroprevalence and isolation of Toxoplasma gondii from free-range chickens from Espírito Santo state, southeastern Brazil

“…The seroprevalence of T. gondii in humans and the burden of disease in congenitally infected children in Brazil are highest are among the countries in the world (Gilbert et al, 2008;Dubey, 2010a). Espírito Santo of the strains prevalent in the environment, as FR chickens become infected mostly by feeding from soil contaminated with oocysts (Ruiz and Frenkel, 1980).…”

Ocular manifestations of congenital toxoplasmosis

“…To explain this fact, it can be postulated that the parasite genotypes presented in our region are more virulent than the ones existing in other regions of the world. 32,[35][36][37] Bilateral ocular involvement occurred in 75.8% of the cases, thus showing the broad involvement of the nervous system by the parasite during the fetal stages of development. This finding had already been noted since the first descriptions of the disease, which showed that bilateral involvement is a typical characteristic of congenital toxoplasmosis.…”

Toxoplasmosis and psychosis: environment makes a difference

“…Among those born with congenital toxoplasmosis 9% of cases have significant visual impairment. The rates of visual impairment from congenital toxoplasmosis in the three to four years after birth are much lower in the United States as compared to Europe (29%) and Brazil (87%) [7,11].…”