Influenza A virus infection imitating bacterial sepsis in early infancy.

Clinical and laboratory data of 12 previously healthy infants under 3 months of age hospitalized for suspected sepsis and subsequently diagnosed as suffering from influenza A viral infection were obtained prospectively during two epidemics of influenza A/Bangkok/H3N2 epidemics. The onset of the illness was generally acute, and the infants presented with high fever, lethargy often alternating with irritability, anorexia and signs of upper respiratory tract infection. History of contact with at least one person with signs and symptoms consistent with viral disease was present in all infants. White blood cell counts were within normal limits. Only one child had pneumonia and all had normal cerebrospinal fluid findings. Viral diagnosis was made by immunofluorescent testing of nasopharyngeal specimens within several hours of admission in 7 of the 9 infants tested and was isolated within 5 days from admission in 6 of 10 infants. Increasing awareness of the possible viral etiology of acute fever along with a greater availability of rapid viral diagnosis should result in better management of these young infants.