Dual Infection of Infants by Human Metapneumovirus and Human Respiratory Syncytial Virus Is Strongly Associated with Severe Bronchiolitis

TLDR

The study examined whether dual infection with human metapneumovirus and respiratory syncytial virus is linked to severe bronchiolitis in infants admitted during the 2001–2002 winter season. hMPV was detected by reverse‑transcriptase PCR in nasopharyngeal aspirates and bronchoalveolar lavage samples, while hRSV was identified by enzyme immunoassay, tissue culture, and RT‑PCR in the same specimens. Infants with dual hMPV/hRSV infection had a 10‑fold higher risk of requiring mechanical ventilation in the pediatric intensive‑care unit and were more likely to develop severe bronchiolitis.

Abstract

The association between severe bronchiolitis and dual infection by human metapneumovirus (hMPV) and human respiratory syncytial virus (hRSV) was investigated in !2-year-old infants with bronchiolitis who were admitted to the hospital during the 2001–2002 winter season. hMPV in nasopharyngeal aspirate and/or cells and fluid collected by nonbronchoscopic bronchoalveolar lavage was detected by reverse transcriptase-polymerase chain reaction (RT-PCR). hRSV was detected in nasopharyngeal aspirate and/or cells and fluid collected by nonbronchoscopic bronchoalveolar lavage by enzyme immunoassay, tissue culture, and RT-PCR. Dual infection with hMPV and hRSV confers a 10-fold increase in relative risk (RR) of admission to a pediatric intensive-care unit for mechanical ventilation (RR, 10.99 [95% confidence interval, 5.0–24.12]; P < .001, by Fisher exact test). Dual infection by hMPV and hRSV is associated with severe bronchiolitis.