Human rhinovirus linked to bronchiolitis and upper respiratory infections among healthy term infants
Research Activities October 2011, No. 374
Human rhinovirus (HRV) infections have been known to provoke asthma attacks in adults and children. Now a new study adds to the evidence that HRV infections are a frequent cause of bronchiolitis (inflammation of the narrow airways in the periphery of the lungs) and uncomplicated upper respiratory tract illnesses (URIs) in previously healthy term infants. Relatively little attention has been paid to the role of HRV in respiratory diseases in infants.
The researchers examined 630 infants with bronchiolitis or URIs. Of these, 26 percent had HRV infections, comprising 18 percent of the cases of bronchiolitis and 47 percent of the cases of URIs. The majority of HRV-infected infants (64 percent) had negative tests for a panel of seven other common respiratory viruses, and 42 percent of the infants testing positive for HRV alone were hospitalized. Among infants infected with HRV, a diagnosis of bronchiolitis instead of a simple URI correlated with white race (57 percent with bronchiolitis vs. 30 percent with URI), coinfection with another virus (42 vs. 11 percent), and a history of allergic sensitivity, called atopy, in the mother (54 vs. 40 percent).
After taking into account the age, race, and sex of the infant and exposure to smoking in the home, cases of HRV-associated bronchiolitis were 2.39 times as likely to be severe if the mother had a history of atopy and 2.49 times as likely to be severe if the mother had asthma. The prospective study drew on clinical data about and biospecimens from infants under 12 months old seen for bronchiolitis or URI from fall 2004 through spring 2008, as part of the Tennessee Children's Respiratory Initiative. The study was funded in part by the Agency for Healthcare Research and Quality (HS18454 and HS19699).
More details are in "Host and viral factors associated with severity of human rhinovirus-associated infant respiratory tract illness," by E. Kathryn Miller, M.D., M.P.H., John V. Williams, M.D., Tebeb Gebretsadik, M.P.H., and others in the April 2011 Journal of Allergy and Clinical Immunology 127(4), pp. 883-891.