title: Hepatitis B virus infection in two Gambian villages.
abstract: The prevalence of hepatitis B virus infection was markedly different in two neighbouring Gambian villages. 62% of children in Manduar aged 2-4 years were infected whereas in Keneba, the other village, only 27% of this age-group were infected. However, in both villages few infants were infected--none under 6 months of age and only 2 of 58 between the ages of 6 and 12 months. Carriage of hepatitis B surface antigen (HBsAg) was high, reaching a peak of 36% in the 5-9 age-group in Manduar and 17.6% in the 2-4 age-group in Keneba. 86% of all the children under the age of five who were HBsAg-positive also carried hepatitis B e antigen (HBeAg). This proportion fell to 17.6% for children aged 10-14 years and to 12.9% for mothers. Infection clustered in families, transmission from sib to sib being of major importance. The chances of a child being an HBsAg carrier were approximately 42% if an elder sib carried the antigen, 27% if either mother or father was a carrier, and 15% if neither mother or father was a carrier. There were 4 HBeAg-positive mothers who were highly infectious, since 10 of 11 of their children became HBsAg carriers. Carriage of surface antigen lasted many years; 63% of those carrying the antigen in 1972 were still positive in late 1980. 4 cases of primary hepatocellular carcinoma out of 672 adults have been diagnosed in the past five years. All 4 were in HBsAg carriers.
mesh_terms: D000367:Age Factors; D006528:Carcinoma, Hepatocellular / Q000097:blood / Q000453:epidemiology; D002353:Carrier State / Q000453:epidemiology / Q000635:transmission; D002648:Child; D002675:Child, Preschool; D005714:Gambia; D006509:Hepatitis B / Q000453:epidemiology* / Q000635:transmission; D006510:Hepatitis B Antibodies / Q000032:analysis; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006513:Hepatitis B e Antigens / Q000276:immunology; D006515:Hepatitis B virus / Q000276:immunology; D006801:Humans; D007223:Infant; D008113:Liver Neoplasms / Q000097:blood / Q000453:epidemiology; D012423:Rural Health
chemical_list: D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens