Respiratory Syncytial Virus: An Association with Severe Asthma Exacerbations in Children of All Ages

Abstract

Respiratory viruses are known to cause asthma exacerbations. There have been no previous studies in children looking at which viruses have the greatest capacity to induce an asthma exacerbation. This study attempts to identify viruses with the most asthmagenic properties. The objective of this study is to determine the prevalence of viral infections in children with asthma exacerbations, and to correlate specific viral infections with clinical severity. Nasopharyngeal and oropharyngeal swabs were collected for viral culture from 101 asthma patients presenting to the Children's Hospital of Philadelphia Emergency Department with an asthma exacerbation. Patients ranged in age from 3 years to 18 years. One hundred and one well asthmatics were recruited from the Allergy Clinic and Department of Pediatrics to serve as control patients. Control patients were enrolled within 2 weeks of study patients, and were matched by age, gender, and ethnic group. Viral isolates were correlated with the age, gender, ethnic group, and for children with asthma exacerbations disposition. There was a statistically significant (Fisher's exact test p = 0.022) increase in culture-proven viral isolates in children with asthma exacerbations (14.9%), as compared with well asthmatic children (3.0%). Respiratory synctial virus was the most prevalent virus isolated, representing 46.7% [95%, Confidence interval (17.8, 69.3)] of all viral isolates. There also was a statistically significant increase in RSV isolates (p = 0.0269) from patients requiring pediatric intensive care compared with asthma patients with less severe exacerbations. Viral infections are common triggers of asthma exacerbations in children, and RSV is associated with the most severe exacerbations in children of all ages. Prevention, and/or treatment of RSV infection should be considered a high priority for the management of asthmatic children.