Background: Upper respiratory infections (URIs) are particularly likely to affect young children. Up to one half of URIs are complicated by otitis media, which is one of the most common diseases in children. Because of this, URIs are indirectly responsible for widespread antibiotic use and otologic surgical procedures. Chonmaitree and colleagues conducted a prospective longitudinal cohort study to determine whether specific viral strains are more likely to result in otitis media–complicated URIs, which could aid the development of vaccines for otitis media prevention.

The Study: The researchers recruited healthy children six months to three years of age. During the one-year study, parents contacted the investigators when their child had possible URI symptoms (e.g., rhinorrhea, nasal congestion, fever, sore throat, cough). Children were clinically assessed, and those diagnosed with a URI were evaluated with pneumatic otoscopy and tympanometry. Nasal and nasopharyngeal specimens were also collected for virologic studies. The children were reevaluated two and three weeks later, and those with abnormal tympanogram results were retested every two weeks until the findings normalized. Otitis media diagnosed within 28 days of URI symptoms was considered to be a complication of the URI.

Results: Of the 294 children enrolled in the study, 201 were observed for the entire year. The mean duration of follow-up per child was 9.8 months. A total of 1,295 URI episodes were diagnosed, for a rate of 5.06 episodes per child-year. Out of all URI episodes, 414 (32 percent) were complicated by acute otitis media. Another 26 episodes of acute otitis media were unrelated to a URI.

For the 864 URI episodes with available virus data, 319 (37 percent) developed acute otitis media, and 203 (24 percent) developed otitis media with effusion. Twenty-eight cases were found to have preexisting middle ear effusion and were eliminated from further analysis. Younger age and virus type were significantly associated with the development of acute otitis media after URI. Adenovirus, respiratory syncytial virus, and coronavirus were the most common viruses identified, with about 50 percent of URIs from these organisms being complicated by acute otitis media. Other viruses (i.e., influenza, rhino-virus, enterovirus, and parainfluenza) had significantly lower rates of complications, with approximately one third of related URIs subsequently developing acute otitis media.

Conclusion: The authors found that more than 60 percent of URIs in young children were complicated by the subsequent development of otitis media. Future strategies to prevent relevant infections should be investigated.