Polymicrobial respiratory tract infections in a hospital-based pediatric population, with particular emphasis on the role of human rhinoviruses

Abstract

Pediatric acute respiratory tract infections (ARTIs) are a leading cause of morbidity and mortality. The objectives of this study were to describe the epidemiology of polymicrobial ARTI in a hospital-based pediatric population and to investigate the association of polymicrobial infection and severity of illness. We conducted a retrospective study of 559 archived respiratory specimens from 421 children under the age of 10 years collected from March 28, 2008 through June 30, 2009 and stored by the University of Iowa Hospital and Clinics Clinical Microbiology Laboratory. Specimens were tested by direct immunofluorescent assay and/or viral culture at the time of collection (influenza A and B, parainfluenza [PIV] 1-3, respiratory syncytial virus [RSV], adenovirus [Ad]) and uniformly by RT-PCR (human metapneumovirus [hMPV], rhinovirus [HRV], human bocavirus [HBoV]) and PCR (Ad) for the current study. Demographic and clinical data were abstracted from electronic medical records. Results from this study suggest that polymicrobial respiratory tract infections are common in this population. A virus was identified in 61.3% of 349 respiratory specimens from children with confirmed or suspected ARTI. HRV (27.5%), RSV (18.9%), HBoV (8.3%), hMPV (7.7%), and PIV (6.6%) were the most common viruses detected. A viral coinfection was identified in 21.5% of the 214 virus-positive specimens and was most often detected for Ad (53.3% of 15 Ad-positive specimens), HBoV (51.7% of 29 HBoV-positive specimens), PIV (43.5% of 23 PIV-positive specimens), HRV (35.4% of 96 HRV-positive specimens), and RSV (34.8% of 66 RSV-positive specimens). Among the 46 specimens with dual or triple viral coinfections detected, the most frequent virusvirus combination was HRV-RSV (n=12).