Rhinoviruses Are a Major Cause of Wheezing and Hospitalization in Children Less Than 2 Years of Age

Background: Human rhinoviruses (HRV) are now considered major respiratory pathogens. We Sought to determine whether HRV are a cause of wheezing and/or hospitalization in children < 2 years old. Methods: A polymerase chain reaction assay Was used to screen for HRV infection in 4 categories of children < 2 years old: (1) with symptoms or respiratory tract disease Without wheezing; (2) with wheezing with or Without other symptoms; (3) who were asymptomatic and; (4) who had a respiratory specimen submitted to a diagnostic laboratory. All specimens were collected between January and December 2004. Phylogenetic analyses were performed oil most HRV isolates. Results: Twenty-eight (17%) of 165 children with symptoms of respiratory infection without wheezing; 21 (26.3%) of 80 children with wheezing; 3 (3%) of 93 asymptomatic children; and 47 (23.3%) of 202 children with specimens submitted to the diagnostic laboratory tested positive for HRV. The difference between the rates of infection in the asymptomatic group and in each of the 3 other categories was statistically significant (P :5 0,01). Among HRV-positive children with samples submitted to the diagnostic laboratory, 55% were hospitalized, which was similar to that observed for respiratory syncytial virus (52.7%) among children of a similar age group and time period (P = 0.85). Diverse groups of HRV were circulating during the 1-year study period. Conclusions: HRV are important pathogens among children < 2 years old and are responsible for a significant proportion of wheezing this age group, The hospitalization rates of HRV-positive children seem to be similar to that of respiratory syncytial virus.