Among healthy, term infants, not being infected with respiratory syncytial virus (RSV) in the first year of life is associated with a substantially lower risk for developing childhood asthma, according to a study published online April 19 in The Lancet.
Christian Rosas-Salazar, M.D., from Vanderbilt University Medical Center in Nashville, Tennessee, and colleagues evaluated the association between RSV infection during infancy and childhood asthma. The analysis included 1,741 healthy infants with non-low birthweight, born at term between June and December 2012 or 2013, with RSV infection status in the first year of life determined using a combination of passive and active surveillance with viral identification through molecular and serological techniques.
The researchers found that the proportion of children with five-year current asthma was lower among those without RSV infection during infancy (16 percent) than those with RSV infection during infancy (21 percent). A lower risk for five-year current asthma was seen among those not infected with RSV during infancy versus those infected with RSV during infancy (adjusted relative risk, 0.74). By avoiding RSV infection during infancy, an estimated 15 percent of five-year current asthma cases could be prevented.
“To our knowledge, this is the first prospective birth cohort study to show an age-dependent and severity-dependent association between RSV infection during infancy and childhood asthma,” the authors write.
