Nearly every child is infected with respiratory syncytial virus (RSV) early in life. The virus usually clears up in a week or so, but in some cases, this “harmless” virus may persist and lead to chronic lung diseases like asthma, according to Reuters Health.
Researchers found that RSV can stay in the lungs of some mice and cause overactive airway symptoms associated with asthma. Previously, doctors thought that the body quickly cleared itself of this virus. Read more about asthma and RSV