Risk factors and prevalence of antibodies against hepatitis A virus (HAV) in children from day-care centers, in Goiania, Brazil Fatores de risco e prevalência de anticorpos contra o vírus da hepatite A (VHA) em crianças de creche em Goiânia, Brasil

Abstract

A seroepidemiologic survey about hepatitis A virus (HAV) infection was carried out in a group comprising 310 children, ranging in age from 3 months to 9 years, from day-care centers, in Goiania, a middle sized city in the central region of Brazil. The biomarkers employed in the investigation of previous infection include total IgG and IgM anti-HAV antibodies, and for the detection of more recent infection, IgM anti-HAV antibodies were analyzed. The study was performed in 1991 and 1992. According to the results, 69.7% of the children presented total IgG/IgM anti-HAV antibodies, with 60% of the group in the age range of 1 to 3 years. Among 10 day-care centers analyzed, the prevalence of the biomarker IgM anti-HAV was 3.2%, with an uniform distribution of the cases in the group of children ranging in age from 1 to 4 years. Multi-variate analysis was performed to investigate the sociodemographic factors that could influence the results. It was verified that the risk for the infection increased with the length of the attendance in the day-care centers, i.e., the risk for children with attendance of one year or more was 4.7 times higher, when compared with children with one month attendance (CI 95% 2.3-9.9). According to the results, hepatitis A is an endemic infection in day-care centers in the study area. The length of attendance in the day-care settings was demonstrated to be a risk factor for the HAV infection. Such findings suggest that if hepatits A vaccination becomes available as a routine policy in our region, the target group should be children under one year. Moreover, those children should receive the vaccine before they start to attend the day-care centers.Um estudo soroepidemiológico para o vírus da hepatite A (VHA), investigando os marcadores de infecção passada (anti-VHA total - IgG e IgM) e infecção recente (anti-VHA IgM), foi realizado entre 1991 e 1992, em crianças de creche de Goiânia-Brasil central. Das 310 crianças com idade entre 03 meses e 09 anos, 69,7% mostraram soropositividade ao anti-VHA total, sendo 60%, na faixa etária entre 1 e 3 anos. A prevalência do marcador anti-VHA IgM foi de 3,2%, visto em idade de 1-4 anos e com distribuição uniforme nas 10 creches estudadas. Entre as variáveis sócio-demográficas estudadas, apenas o tempo de freqüência das crianças nas creches, igual ou superior a um ano, mostrou, em análise multivariada ajustada para idade, um risco 4,7 vezes maior quando comparado com o período de um mês (LC 95% 2,3-9,9). De acordo com os resultados, a hepatite A é uma infecção endêmica no tipo populacional estudado e o tempo de freqüência prolongado das crianças, nas creches públicas, constitui um fator de risco para infecção ao VHA. Tais resultados sugerem que, uma vez que a vacina seja instituída na região, as crianças de creche devem recebê-la antes de um ano de idade, ou no mais tardar antes de ingressarem nas creches públicas.

Keywords

• Hepatitis A survey
• Seroepidemiology
• Day-care children