The prevalence of asthma is increasing, with up to one in four urban children now affected. Episodes may be triggered by environmental factors, exertion, emotional stress or infection. A recent study by research workers at the University of Texas Southwestern Medical Center, which is available in the Nov 15 issue of the Journal of Infectious Diseases, suggests that infection with respiratory syncytial virus (RSV) may lead to recurrent wheezing, even after the acute symptoms of infection have resolved. The study, which was carried out in mice, showed a striking correlation between the amount of virus detected in the lungs of the mice with the severity of airway hyper-reactivity. The group had previously shown that mice infected with RSV were more likely to develop chronic lung disease than uninfected mice. They also found that treatment of the infected mice with an anti-RSV antibody reduced the amount of virus in the lungs as well as the extent of hyper-reactivity and inflammation in the lungs.
Almost all children have had at least one RSV infection by the age of three, and a study is currently underway to determine whether treating children with an antibody against RSV can prevent wheezing during a one year follow-up period. The findings could lead to the development of treatments for children with recurrent wheezing caused by RSV infection.