Infection with influenza virus type A is a common etiology of illness in infants and children during the winter months. It is estimated that rates of this virus may be as high as 40 percent annually. Physicians use various diagnostic tests to distinguish between viral and bacterial infections. In addition, antibiotics are commonly given empirically to infants and toddlers with influenza. With the renewed emphasis on reducing antibiotic use and the need to decrease unnecessary diagnostic testing, strategies to identify influenza in this age group could be beneficial. A rapid detection test for influenza virus type A is performed using an enzyme-linked immunosorbent assay (ELISA), which is as specific and sensitive as viral cultures. Sharma and associates studied the effect of the rapid diagnosis of influenza A on the clinical management of febrile infants and toddlers.

A retrospective chart review was performed for all children between two and 24 months of age who visited the emergency department with a temperature higher than 39°C (102.2°F) and a positive ELISA test for influenza A. The study consisted of reviewing the care received by infants who had a positive test reported before discharge from the emergency department (early diagnosis) and those whose positive test result was known after discharge (late diagnosis). Data collected included triage status, date and time the ELISA test was ordered and performed, other ancillary tests, antibiotics given, and hospitalization information for those admitted.

The study group consisted of 72 infants, with 47 in the early diagnosis group and 25 in the late diagnosis group. Both groups were similar in age, temperature, and triage category. Infants in the early diagnosis group were significantly less likely to undergo urine testing and complete blood counts than those in the late group. In addition, those in the early diagnosis group were less likely to receive therapy with ceftriaxone sodium than those in the late diagnosis group. Rates of chest radiography and hospital admittance did not differ between the two groups.

The authors conclude that the ELISA test for influenza A infection in febrile infants and toddlers seems to decrease the number of ancillary tests and reduce the use of antibiotics. The use of this test in the care of febrile infants and toddlers may have an impact on management of these patients. The authors add that this was a retrospective study and should be followed by a larger, prospective study.