Hepatitis

The incidence and spread of HAV is directly related to poor personal and social hygiene and is a serious problem not only in developing countries where sanitation and water purification standards are poor, but also in developed, industrialized nations—including the United States, where it accounts for 30% of all incidences of clinical hepatitis. Except in 1% to 4% of cases where sudden liver failure may result in death, chronic liver disease and serious liver damage very rarely develop, and "chronic carrier state," in which infected people with no visible symptoms harbor the virus and transfer the disease to non-infected individuals, never occurs. Also, reinfection seldom develops in recovered HAV patients because the body eventually develops antibodies, cells which provide a natural immunity to the specific virus attacking the host. Although HAV is self-limiting (after time, ends as a result of its own progress), there is as yet no effective treatment once it is contracted.