An epidemic of rotavirus-associated gastroenteritis in a nursing home for the elderly.

92 cases of acute gastroenteritis were registered among 256 individuals during an outbreak in a nursing home for the elderly, the majority of patients being between 70 and 90 years of age. Most cases appeared in 4 of the 8 wards; 66% of the inmates of these wards became ill. Characteristic symptoms were initial nausea and vomiting followed by diarrhoea and low fever. A number of patients were severely ill. One patient died. Rotavirus infection was diagnosed by virus detection and/or antibody titre rise during the acute phase of the illness in 13 of 16 patients examined. At the end of the outbreak, high titres of complement-fixing antibodies against rotavirus (greater than or equal to 64) were detected in serum from 21/22 patients convalescing from the disease, as compared to only 5/45 individuals with no signs of disease. It is tentatively suggested that the outbreak became extensive and rather severe because of lowered immunity against rotavirus infection among the elderly.