Middle ear abnormalities at age 5 years in relation with early onset otitis media and number of episodes, in the Inuit population of Nunavik, Quebec, Canada.

Otitis media (OM) and their sequelae are a major health issue in the Inuit population of Nunavik, Quebec. Hypotheses of the study were: (i) early onset OM leads to repeated OM; (ii) repeated OM episodes leads to middle ear abnormalities (MEA) at age 5 years, (iii) pneumococcal conjugate vaccines (PCVs) may reduce multiple OM and MEA. Immunisation cards, medical records and audiology screening tests at age 5 years in a sample of 610 children born in 1994-2010 in 3 communities were reviewed. Children were classified into three categories using a score based on audiology screening tests: no abnormality, minor, or major MEA. The average number of OM episodes before age 5 years was 5.0 and 30% had minor and 17% major MEA at age 5 years. Community residency predicted both frequent (≥ 8) OM episodes and MEA. Early onset OM (age <6 months) was a predictor of frequent OM (RR = 1.71; 95%CI: 1.50-1.95) whereas PCV (≥1 dose ≥ age 2 months) has no significant effect. Frequent OM episodes were associated with major MEA (RR = 2.16; 95%CI: 1.20-3.85). Although associations were not statistically significant, there was a trend towards a protective effect of PCV administration on frequent OM and minor MEA, but not major MEA. In conclusion, results support an association between early onset OM, frequent OM and MEA that could represent a causal pathway.