Objective: To determine the amount of and rationale for antibiotic use in a cohort of children with lower respiratory tract infection(LRI) secondary to the respiratory syncytial virus (RSV).

Design: Prospective observational cohort study.

Subjects: Patients less than 2 years of age admitted to a tertiary care pediatric hospital with a clinical diagnosis of LRI and positive direct immunoflourescence microscopy for RSV were eligible. Patients greater than 2 years with underlying cardiac abnormalities, respiratory disease or immunosuppression were also eligible. Patients were enrolled as part of the PICNIC study of RSV-related LRI (J Peds 1995).

Results: One hundred and fifty-two patients were enrolled between Jan. and May 1993; median age 5.6 months (range 0.2-151 mos); male to female ratio 1.6:1. Morbidity was comparable to previously reported cohorts and no patients died. Ninety-two (60.5%) patients received at least one antibiotic during hospitalization (65 oral and 44 IV). Documented reasons for antibiotic prescription included otitis media (37%), “pneumonia”(31%) and suspected sepsis (.08%). In those receiving IV antibiotics, only 32%(14) had the medication discontinued once RSV infection was confirmed. Of the remaining 30 patients who continued on IV antibiotics, 10 had positive blood(5) or urine (5) cultures and 15 had no clearly defined bacterial etiology or rationale documented. Twenty-three patients received 1 IV antibiotic, 20 received 2-6 types and 1 had nine antibiotic changes. Patients given ribavirin were more likely to receive an antibiotic than those not given ribavirin (88% vs 55%, p<.005). Eleven patients suffered an adverse event during their admission, of which 10 (91%) were in children receiving intravenous antibiotics.

Conclusion: This study demonstrated that a high percentage of children admitted to hospital with LRI secondary to RSV received unnecessary antibiotics. We believe that physician education strategies should stress discontinuation of antibiotic therapy once a diagnosis of RSV infection is made in the absence of a clearly defined bacterial co-infection. This could diminish the development of resistant bacteria, reduce health care costs and minimize the potential for adverse events associated with inappropriate antibiotic use. Funded in part by ICN Canada Ltée and Lederle Canada Inc.