Why diagnose influenza infections in hospitalized pediatric patients?

The advent of rapid diagnostic testing for respiratory syncytial virus facilitated decisions for isolation of infectious hospitalized patients. However, diagnosing other viruses by clinical examination such as influenza may be difficult. If patients with influenza are not diagnosed on hospital admission, nosocomial infections may occur. The purpose of our study was to identify patients with nosocomial influenza infections during one winter season in a large children's hospital, document the morbidity, identify potential index cases as roommate exposures who were not identified as having influenza at the time of admission and determine ways in which these cases could have been prevented. From December, 1989, to March, 1990, 74 patients were found to have positive influenza cultures; 11 (15%) were determined to be nosocomial in origin. Hospitalization was extended for 6 patients. Additional costs for these 11 patients resulting from influenza infection totaled +83,000. Six index cases were identified as potential exposures to 7 (67%) of those who acquired nosocomial infections. In none of these potential index cases had influenza been considered as an admission diagnosis. Rapid tests for influenza are necessary to identify patients with influenza at admission and to identify hospitalized patients with nosocomial infection to decrease the number of diagnostic tests and institute appropriate isolation procedures.