Background
Infants aged <90 days who present with fever commonly undergo various invasive procedures due to the risk of bacterial infection in this age group. A great proportion of cases, however, are due to viral infection, including influenza. The aim of this study was therefore to assess the impact of influenza testing in infants <90 days with fever, as well as analyze the subject characteristics to identify which infants should be considered for such testing.
Methods
Clinical characteristics and trends in influenza virus testing and treatment were analyzed among febrile infants <90 days who presented to the emergency room and were diagnosed with influenza during 2005–2015.
Results
Among 5,347 febrile infants aged <90 days, 963 (18%) underwent influenza virus test. A total of 114 (11.8%) were diagnosed with influenza. The positivity rate reached 67% of febrile infants during epidemics. Of them, 83 had a history of family contact. While more than half presented with upper respiratory symptoms, 34% had only fever without respiratory symptoms. A decrease in antibiotic use and admission rates during the study period among infants diagnosed with influenza was seen (P for trend <0.05).
Conclusions
During the influenza epidemic season, diagnostic tests for influenza based on a detailed contact history are necessary in assessing the cause of fever. Targeted testing for influenza may lead to a decrease in antibiotic use and admission rates in young infants.