Detection of respiratory syncytial virus and rhinovirus in healthy infants

Kohei Hasegawa, Rachel W. Linnemann, Vasanthi Avadhanula, Jonathan M. Mansbach, Pedro A. Piedra, James E. Gern, Carlos A. Camargo

Despite the research importance of rhinovirus detection in asymptomatic healthy infants, the literature remains sparse. To investigate the prevalence of respiratory syncytial virus (RSV) and rhinovirus (and its species). We conducted a cross-sectional study of 110 healthy, non-hospitalized infants without acute illness at an academic medical center from November 2013 through May 2014. We tested nasal swab specimens by using polymerase chain reaction and genetic sequencing. Overall, the median age was 3.8 months (IQR 2.0-5.1 months), 56 % were male, and 90 % were born >37 weeks. RSV was detected in nasal swabs from infants (1.8 %). By contrast, rhinovirus was detected in nasal swabs from 16 infants (14.5 %). Molecular typing assay revealed rhinovirus species: six rhinovirus-A (5.5 %), one rhinovirus-B (0.9 %), eight rhinovirus-C (7.3 %), and one untypeable (0.9 %). In this cross-sectional study of healthy, community-based infants, RSV was rare (<2 %) in nasal swabs, while rhinovirus was detected in 14.5 % with a predominance of rhinovirus-A and -C. These finding are important for understanding the clinical significance of rhinovirus detection among infants hospitalized for bronchiolitis.