INCIDENCE OF SERIOUS BACTERIAL INFECTION IN FEBRILE NEONATES LESS THAN 28 DAYS WITH BRONCHIOLITIS

Abstract

BACKGROUND: Bronchiolitis is the most common reason for admission in infants under 12 months of age. There is uncertainty as to whether invasive tests to look for bacterial infections are necessary in febrile infants under 28 days of age who present with clinical findings consistent with bronchiolitis. OBJECTIVES: Several recent reviews suggest that babies 28 to 90 days of age with bronchiolitis are at relatively low risk of serious bacterial infection, with the exception of urinary tract infection (UTI). There has been no literature to date focusing exclusively on infants less than 28 days. DESIGN/METHODS: We conducted a multi-center retrospective chart review to determine the proportion of febrile infants less than 28 days of age admitted with bronchiolitis who were ultimately found to have a bacterial infection in their blood, urine, or cerebrospinal fluid. At each site all charts between March 2006 and May 2015 with an admission to hospital at age less than or equal to 28 days with a discharge diagnosis of bronchiolitis were reviewed. Exclusion criteria included lack of documented fever, gestational age at birth less than 36 weeks, known immunodeficiency, hemodynamically significant congenital heart disease, or congenital lung anomaly. RESULTS: Our sample included 226 neonates. There were 57 positive urine cultures, of which 34 were considered by the treating team to be contaminants, for a rate of UTI of 23 in 226, or 10.1%. Of the 23 UTIs, 16 had colony counts that were consistent with contamination based on the current CPS statement but which were treated as true infections. There were 6 positive blood cultures, of which 5 were considered to be contaminants, for a rate of bacteremia of 1 in 226. There were 2 positive cerebrospinal fluid (CSF) cultures. Both of the positive CSF cultures were considered to be contaminants, for a rate of meningitis of 0 in 226. CONCLUSION: Our results are consistent with those of studies in older infants in documenting an extremely low rate of serious bacterial infection other than UTI in infants less than 28 days admitted with clinical bronchiolitis, even though these febrile neonates have traditionally been thought to be at highest risk. This suggests that invasive CSF sampling and empiric antibiotic administration in this population may be safely avoided, though this would have to be confirmed in large-scale prospective studies. In our sample there was a significant risk of contamination and false positive bacterial cultures.