Transmission of Influenza Virus From Asymptomatic Healthcare Workers and Inpatients in the Acute Care Hospital Setting

The epidemiology and transmission dynamics of influenza in hospitals are only poorly understood, particularly with respect to subjects without symptoms of influenza infection (e.g. without fever, cough, sore throat, nasal congestion, weakness, headache, loss of appetite, or myalgia). Knowledge about whether asymptomatic subjects are able to transmit influenza is of major importance. If they do transmit influenza, vaccination of patients and healthcare workers (HCW) before start of the influenza season, the permanent use of masks by HCW during influenza season, and quarantine for previously exposed inpatients may be the only available measures to reduce the number of influenza transmission events from asymptomatic subjects in acute care hospitals. Closure of this knowledge gap would be of major benefit to infection prevention and control recommendations, and may in turn reduce morbidity and mortality associated with influenza in hospitals through improved patient management.