Prevalence of hepatitis A virus antibody among Navajo school children.

Previous studies of the prevalence of immunity to hepatitis A (anti-HAV) in the United States have used urban settings or institutions for the mentally handicapped. In a rural setting among normal children, a serologic investigation of prevalence of anti-HAV was conducted in a boarding school adjacent to the Navajo reservation. The results show rates of anti-HAV that are the highest reported at the ages tested in any subpopulation in the United States, comparable only with those in developing countries.