HEPATITIS-B VIRUS-INFECTION IN GENERAL-POPULATION IN MADAGASCAR - EVIDENCE FOR DIFFERENT EPIDEMIOLOGIC PATTERNS IN URBAN AND IN RURAL-AREAS

To describe the features of hepatitis B virus (HBV) infection in Madag ascar, a randomized sero-epidemiological survey was undertaken in the general population greater than or equal to 1 year old of two province s which represents 45% of the total population. In the 921 sera tested , the prevalence of HBV markers was 20.5% for HBsAg, 38.2% for anti-HB c and 6.9% for HBeAg. HBsAg and anti-HBc prevalence rates were signifi cantly higher in males. A large difference in HBsAg prevalence was obs erved between urban (5.3%) and rural areas (26.0%). The same contrast in prevalence was noticed for the other HBV markers. In rural areas, H BV infection was more frequently acquired early in infancy, which sugg ests predominantly perinatal or postnatal transmission. The presence o f HBV markers was not significantly associated with a history of blood transfusion, surgery or parenteral injection. High infectivity carrie rs represented 5.3% and the overall frequency of chronic carriers was 10.4%. These results place Madagascar among areas of high endemicity.