[Prevalence of hepatitis B viral markers in children 3 to 9 years old in a town in the Brazilian Amazon].
OBJECTIVE
To estimate the prevalence of hepatitis B infection and to identify possible means of transmission in children from 3 to 9 years of age in Peixoto de Azevedo, a town in the Brazilian Amazon.


METHODS
A cross-sectional study was carried out with 487 children enrolled in public schools and day-care centers. We obtained data concerning migration, medical history, exposure to classical risk factors for hepatitis B infection, socioeconomic factors, and the habit of sharing a bed or personal objects. We also investigated the presence in the home of persons with sexually transmitted diseases, injecting drug users, heavy alcohol users, men who had sex with other men, persons with multiple sexual partners, and a history of jaundice or hepatitis or of receiving a transfusion of blood products. Blood samples were obtained from the children to test for viral markers.


RESULTS
The prevalence of hepatitis B viral markers was 11.1% (54 of 487 children). Six of the children (1.2%) tested positive for hepatitis B surface antigen. There was no association between viral markers and economic conditions, parental schooling, sanitary conditions (e.g., source of drinking water, method of wastewater disposal, method of trash disposal), number of rooms in the home, the child's history of jaundice or hepatitis, dental treatment, any accidents with needles or syringes, reusing needles or syringes, transfusion of blood products, and the habit of sharing a bed or personal objects. However, children who had contact with heavy alcohol users tended to have a higher prevalence of viral markers (P = 0.06). Among the children studied, 53 of them (10.9%) had received one or two doses of hepatitis B vaccine, but none had completed the three-dose series. Logistic regression showed that an increased prevalence of viral markers was associated with a maternal history of jaundice during the pregnancy, more than eight persons living in the home, and the mother not working in a professional occupation.


CONCLUSIONS
Hepatitis B is probably moderately endemic in the population of Peixoto de Azevedo, with transmission mainly occurring horizontally. Such factors as being exposed in the home to persons who are heavy users of alcohol are probably important determinants of infection in the first decade of life. The low vaccination coverage promotes free circulation of the virus.
Universidade Federal de Mato Grosso (UFMT), Departamento de Pediatria, Núcleo de Estudos de Doenças Infecciosas e Tropicais, Cuiabá (MT), Brasil. sandrassis@terra.com.br
Sandra Breder
SB
Assis
Joaquim Gonçalves
JG
Valente
Cor Jesus Fernandes
CJ
Fontes
Ana Maria Coimbra
AM
Gaspar
Francisco José Dutra
FJ
Souto
D001938:Brazil; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006509:Hepatitis B / Q000097:blood* / Q000453:epidemiology*; D006510:Hepatitis B Antibodies / Q000097:blood*; D006514:Hepatitis B Surface Antigens / Q000097:blood*; D006801:Humans; D008297:Male; D016036:Seroepidemiologic Studies
D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens