Seroepidemiological study of infectious mononucleosis in older patients.

In southern Tasmania, Australia, primary Epstein-Barr virus infection occurs in adults greater than 30 years of age at a higher frequency (approximately 13% of all cases) than is generally reported for other parts of the world, and approximately 7% of the general population of the region have no antibodies to the virus. Epstein-Barr virus should not be overlooked as a possible cause of disease in older patients in similar populations elsewhere.