Seroprevalence of hepatitis A antibodies in a group of normal and Down syndrome children in Porto Alegre, Southern Brazil

Abstract

The high incidence of Hepatitis A and B in institutionalized patients with Down Syndrome (DS) is not fully understood. Under poor hygienic conditions, immunological alterations might predispose individuals to these infections. Sixty three DS children between 1 and 12 years old living at home with their families were examined for anti-HAV and compared to age-matched controls (64 healthy children). This cross-sectional study was carried out from May, 1999, to April, 2000, at the Hospital de Clínicas of Porto Alegre, southern Brazil. Groups were compared in terms of age, sex, skin color, and family income (> R$ 500 and < R$ 500/ month) by the chisquare test, with Yates’ correction and for the prevalence of anti-HAV (Fisher’s exact test). In the DS group (n=63), the mean age was 4.4 ± 3.3 years, 94% of the patients were white and 51% were female. Family income was ≤ R$ 500/month in 40 cases (63%). In the control group (n=64), the mean age was 4.8 ± 2.7 years, 81% of the patients were white and 56% were female. Family income was ≤ R$ 500 in 20 patients (31%). DS children’s families had a significantly lower income (P<0.0005). In the DS group there were 6 positive (9.5%) anti-HAV cases, and all came from low-income families (less than R$ 500/ month). In the control group, 3 cases (4.7%) were positive for anti-HAV (two were from a low-income family and one was from a higher income family). These differences were not significant. Our data indicate that Hepatitis A is not a special risk for mentally retarded DS outpatients, even in a developing country like Brazil.