Temporal relationships for cold-like illnesses and otitis media in sibling pairs

Background: New otitis media (OM) episodes are most frequently a complication of cold-like illnesses (CLIs) which are often virus infections that can be exchanged within the family unit. Interference with intrafamily CLI transmission may present a strategy for OM prophylaxis in high risk children. This study estimated factors relevant to strategy efficiency. Methods: Two siblings (ages, 1.0-4.3 and 1.7-6.1 years) from 69 families were followed for 193 days beginning in October using daily parental diaries focused on CLI signs and weekly pneumatic otoscopy to diagnose OM presence/absence. An algorithm converted the signs to presence/absence of a cold-day; cold-days were grouped into CLI episodes, and episodes were examined for intersib transmission and OM complications. Results: We identified 267 CLIs in the younger siblings and 221 in the older siblings. Twenty-seven percent of the CLI episodes in one sibling occurred after CLI onset in the other with a median interval of 3 days. Sixty-two percent of newly diagnosed OM episodes occurred during a CLI and 27% of CLIs were complicated by OM. Analysis of factors that could affect CLI incidence documented significant contributions of gender, age, daily environment and the CLI burden in the sibling with expected directionalities. Conclusion: The results document intrafamily transmission of CLIs that is often associated with the development of OM as a complication. These observations and the measured interval between primary and secondary CLI onsets support the possibility of preventing OM by strategies that target intrafamily CLI transmission.