Objective: We evaluated the presentation, outcomes, and the risk of serious bacterial infection (SBI) in infants <3 months old with influenza virus infection.
Patients and Methods: We identified demographic, hospitalization, and microbiologic data from computerized medical records for all infants and children <24 months of age, with laboratory confirmed influenza infection cared for at a tertiary care children's hospital during 4 winter seasons (2004–2008). We compared those <3 months of age with older groups.
Results: We identified 833 children <24 months of age with laboratory-confirmed influenza. Of those, 218 were <3 months old. Influenza accounted for 3.6% of all evaluations of febrile infants and 12% of febrile infant encounters during winter. Infants <3 months of age were less likely to have a high risk chronic medical condition, but were more likely to be hospitalized than children 3 to <24 months old (P < 0.005). Infants <3 months with influenza had fewer prolonged hospital stays than those 3 to <6 months old [P = 0.056; OR: 0.5 (0.24–1.0)] and 6 to <12 months old [P = 0.011; OR: 0.43 (0.24–0.83)]. Five (2.3%) infants <3 months old had SBI.
Conclusions: Infants <3 months of age with influenza virus infection often present with fever alone. Although they are more likely to be hospitalized than those 3 to <24 months old, hospital stays are short and outcomes generally good. Infants with influenza virus infection have a low risk of concomitant SBI.
From the *Divisions of Pediatric Infectious Disease and †Inpatient Pediatrics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, Utah; and ‡Department of Pediatrics, Pediatric Specialty Clinical Program, Intermountain Healthcare, Salt Lake City, Utah.
Accepted for publication June 25, 2009.
J.M.B. is the recipient of a NIH Rocky Mountain Regional Center for Excellence in Biodefense and Emerging Diseases young investigator award U54 AI065357. P.G. and C.L.B. are supported in part through the CDC-funded Center of Excellence in Public Health Informatics (CDC 1 PO1 CD000284) at the University of Utah. R.S. is the recipient of a NIH/Eunice Kennedy Shriver NICHD career development award K23 HD052553. C.L.B. is further supported by grants from the Public Health Services research grant UL1-RR025764 from the National Center for Research Resources (NIH/NIAID 1 U01 AI074419 and U01-A1061611), and the NIH/Eunice Kennedy Shriver NICHD K24- HD047249. This project was in addition supported by the Children's Health Research Center at the University of Utah.
Address for correspondence: Jeffrey M. Bender, MD, University of Utah School of Medicine, Department of Pediatrics, Division of Pediatric Infectious Diseases, PO Box 581289, Salt Lake City, UT. E-mail: Jeffrey.Bender@hsc.utah.edu.
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal's Web site (www.pidj.com).