Influenza A among hospital personnel and patients. Implications for recognition, prevention, and control.

An outbreak of influenza A/Philippines H3N2 at a 1156-bed Veterans Administration Hospital involved 118 hospital personnel and 49 patients. Prospective surveillance methods that had been established within the hospital were not useful in identifying the number of involved individuals. Community indicators of influenza, which were reviewed retrospectively, would not have identified circulating influenza in this population. Control of the outbreak was accomplished using a creative approach that immunized over a third of the physician and nursing staff. This immunization program was successfully used in subsequent years to increase personnel compliance with the Immunization Practices Advisory Committee recommendations to annually immunize hospital personnel.