Children with influenza-S. aureus coinfection had a higher frequency of severe outcomes than children hospitalized with influenza or S. aureus alone. Coinfection should be considered in children with severe respiratory illness during the influenza season.
To assess the burden of coinfection with influenza and community-onset S. aureus in hospitalized children, we conducted a retrospective medical record review of all children admitted to Atlanta pediatric hospitals from October 2006 to April 2007 with laboratory-confirmed influenza or S. aureus cultured from a respiratory or sterile site within 72 hours of admission.
Of 65 children with influenza, 7 (11%) had influenza-S. aureus coinfection; an additional 155 had community-onset S. aureus alone. Of S. aureus isolates, 43% were methicillin-resistant. Coinfected children were more frequently admitted to the intensive care unit (71%, P = 0.05) than other children with influenza (28%) or S. aureus (36%) alone and also had a significantly higher case fatality (29%, P = 0.01; 0% influenza, 5% S. aureus). Recent skin or soft tissue infection was documented in 29% of coinfected children, compared with 2% with influenza alone (P = 0.03).
Coinfection with influenza virus and Staphylococcus aureus can cause severe illness or death, and may be increasing. During the 2006-2007 influenza season, 30% of influenza-associated pediatric deaths reported to Centers for Disease Control and Prevention had S. aureus coinfection, compared with 2% to 7% in 2004-2006. The overall occurrence, however, remains unclear.