[Demonstration and occurrence of IgM-type hepatitis A viral antibodies].

Hepatitis-A antibody of the IgM class can be demonstrated in serum by radio-immunoassay quickly, relatively cheaply and simply. The diagnosis of fresh or recent hepatitis-A virus infection can be made from a single serum sample in a single test. Epidemiological analysis of the positive findings obtained in 1981 gave the following results: 1. Hepatitis-A is, in Germany, largely a disease of young adults, with an average age of 24 years. But cases still occurred above the age of 50.2. Among foreigners positive results were obtained already in children (average age 7 years). 3. While in foreigners the disease predominantly occurred in the last four months of the year, among Germans the distribution had three peaks related causally to the holiday months of April, July and October.