Age-specific prevalence of hepatitis A virus antibody in Ethiopian children.

Three groups of individuals in Ethiopia, with different socioeconomic status, were studied demographically and serologically to determine the age-specific prevalence of antibody to hepatitis A virus (anti-HAV). A total of 959 subjects, 89% of whom were children under 15 years of age, were tested for anti-HAV by radioimmunoassay. Evidence of infection started early, found in 50% of the population before 5 years of age, increased rapidly with age and became universal after 15 years of age. A comparison of anti-HAV prevalences between 2 socioeconomic groups (children of health professionals versus children of lower income group) revealed a significant difference (p less than 0.01). These data show that HAV infection in Ethiopia is widespread and that environmental and socioeconomic factors play a major role in its transmission. The widespread prevalence of anti-HAV and anti-HBs also suggest that non-A, non-B virus(es) may be a major cause of the commonly observed sporadic cases of acute viral hepatitis in adult Ethiopians.