Influenza control in acute care hospitals

Background: Influenza causes increased morbidity and mortality among patients in longterm care facilities, but little information is available on the impact of influenza in acute care settings. We wished to have such information when revising our hospital influenza control policy. Methods: We reviewed recent reports of influenza among patients in acute care hospitals and surveyed large (approximately 500-bed) acute care teaching hospitals by telephone to determine the nature of their influenza control policies. Results: Seventeen reports of influenza outbreaks in acute care hospitals were published from 1959 to 1994. Influenza A caused 13 of these outbreaks. Five involved children and 12 involved adults. The mean number of patients in each outbreak was 14 (range 1 to 49), with a mortality rate of 0% to 50% (median 0%, mean 6.5%). Health care workers were implicated in transmission in five reports. Vaccine was used infrequently during the outbreaks, and use of chemoprophylaxis was not reported. Our survey of current practices in 15 university-affiliated hospitals from 12 states revealed that all offered vaccine in the fall but none required either immunoprophylaxis or chemoprophylaxis at any time. Only three had formal policies detailing management of influenza in the hospital. Conclusions: Nosocomial influenza in acute care hospitals is infrequently reported and associated with a low mortality rate. Health care workers rarely comply with preventive measures, and few institutions have formal influenza control policies.