Viral Infections and Associated Factors That Promote Acute Exacerbations of Asthma

Kim, Chang-Keun; Callaway, Zak; Gern, James E.

In the past few decades, highly sensitive and specific tests for virus detection have been developed, resulting in accurate detection of a long list of viruses associated with wheezing in early life, the risk for developing asthma, and exacerbation of established disease. Human rhinovirus (RV) and respiratory syncytial virus (RSV) top the list, but recently discovered or re-emerging viruses (e.g., human metapneumovirus [HMPV] coronaviruses and enterovirus [EV]-D68) also contribute to acute wheezing in infancy and virus-mediated exacerbations. However, most viral infections are not associated with acute exacerations, and cofactors, including allergic inflammation and airway bacteria, have been described that increase the severity of infection and the probability of exacerbation. 1,2 Detection of both viruses and airway bacteria are associated with acute wheezing illnesses; specifically, co-infections of respiratory viruses and Moraxella catarrhalis, Hemophilus influenza, and/or Streptococcus pneumonia increases the risk for more severe respiratory illnesses and exacerbations of asthma. 3 The addition of antibiotics to treatment regimens for asthma exacerbation could materialize in the near future.