Background: Vaccines against respiratory viruses may be able to reduce the frequency of acute otitis media. Although the role of respiratory viruses in the pathogenesis of acute otitis media is well established, the relative importance of various viruses is unknown.
Methods: We determined the prevalence of various respiratory viruses in the middle-ear fluid in 456 children (age, two months to seven years) with acute otitis media. At enrollment and after two to five days of antibiotic therapy, specimens of middle-ear fluid and nasal-wash specimens were obtained for viral and bacterial cultures and the detection of viral antigens. The viral cause of the infections was also assessed by serologic studies of serum samples obtained during the acute illness and convalescence.
Results: A specific viral cause of the respiratory tract infections was identified in 186 of the 456 children (41 percent). Respiratory syncytial virus was the most common virus identified in middle-ear fluid: it was detected in the middle-ear fluid of 48 of the 65 children (74 percent) infected by this virus (P< or =0.04 for the comparison with any other virus). Parainfluenza viruses (15 of 29 children [52 percent]) and influenzaviruses (10 of 24 children [42 percent]) were detected in the middle-ear fluid significantly more often than enteroviruses (3 of 27 children [11 percent]) or adenoviruses (1 of 23 children [4 percent]) (P< or =0.01 for all comparisons).
Conclusion: Respiratory syncytial virus is the principal virus invading the middle ear during acute otitis media. An effective vaccine against upper respiratory tract infections caused by respiratory syncytial virus may reduce the incidence of acute otitis media in children.