Objective: To describe a nosocomial influenza A outbreak, how it was managed, what impact it had on subsequent delivery of health care, and the additional charges attributable to it
Design: Prospective cohort study and microbiological investigation.
Setting: One internal medicine unit in an acute care, university-affiliated hospital.
Participants: Twenty-three patients and 22 staff members from February 28 to March 6, 1999.
Results: Attack rates were 41% (9 of 22) among patients and 23% (5 of 22) among staff members, with 3 of 14 cases being classified as "certain." The influenza virus isolates were typed as A/SYDNEY/5/97 (H3N2). The index case was a patient who shared a room with the first nosocomial case. Vaccination rates for influenza virus were 43% (10 of 23) among patients and 36% (8 of 22) among staff members. The outbreak resulted in staff members' taking 14 person-days of sick leave. Furthermore, 8 scheduled admissions were postponed and all emergency admissions were suspended for 11 days. Hospital charges attributable to the influenza outbreak totaled $34,179 and the average extra charge per infected patient was $3,798.
Conclusions: Nosocomial influenza outbreaks increase charges and alter the quality of care delivered in acute care settings. Strategies for their prevention need to be evaluated in acute care settings.