2009 influenza A in infants hospitalized at younger than 6 months

Objective: To describe the clinical characteristics and outcomes of infants hospitalized at <6 months of age with 2009 influenza A infection. Study design: Prospective laboratory surveillance and discharge International Classification of Disease, 9th edition codes for influenza infection were used to identify all infants hospitalized at <6 months of age with positive influenza A tests at Children's Medical Center Dallas from April 27, 2009 to March 23, 2010. Retrospective chart review then was performed. Results: Seventy-three infants aged <6 months were hospitalized with laboratory-confirmed influenza A infection at a median age of 48 days (range, 3-179 days). The most common clinical characteristics were fever and respiratory signs, and 53% were given a bolus of intravenous fluid. Median length of hospitalization was 2 days (range, 1-162 days). Twenty (27%) infants developed influenza-related complications, including pneumonia (n = 3), hypoxia (n = 18), seizures (n = 2), need for intensive care (n = 8), or death (n = 2). Oseltamivir was administered to 60 (82%) infants and was well tolerated. Conclusions: The majority of infants hospitalized with 2009 influenza A had community-acquired infection that was associated with short hospital stays and favorable short-term outcomes. Complications including death occurred, emphasizing the need for preventive strategies.