Acute otitis media associated with influenza virus infection

We studied 99 children who were diagnosed as having acute otitis media (AOM) associated with influenza A and B virus infection at the Department of Otolaryngology and Pediatrics, Tohoku Rosai Hospital from February to May, 2001 (2001 Season) and from January to June, 2002 (2002 Season). The incidence of AOM were 10.9% of influenza A and 31.7% of influenza B in 2001 Season, and 18.1% of influenza A and 7.3% of influenza B in 2002 Season. The mean age of AOM were 1.4 years old of influenza A and 3.2 of influenza B in 2001 Season, and 1.7 of influenza A and 2.9 of influenza B in 2002 Season. In children below 2 years of age, the incidence of AOM was higher (38.7%). In 97 cases, 54 isolates of Streptococcus pneumoniae, 34 of Haemophilus influenzae and 64 of Moraxella catarrhalis were recovered from the nasal swab. In contrast, only 11 isolates of S. pneumoniae, 7 of H. influenzae and 3 of M. catarrhalis were recovered from the middle ear effusion (MEE) in 80 cases. In 19 cases of influenza B in 2001 Season in which influenza virus antigen detection from MEE were performed by using detection kit, 17 cases were positive. In 43 cases of influenza A in 2002 Season in which influenza virus antigen detection from MEE were performed by using detection kit, viral culture, or RT-PCR, 10 cases were positive in some methods. In 13 cases of influenza B in 2002 Season by detection kit or viral culture, 6 cases were positive. In conclusion, the cases with influenza virus infection were a high risk of AOM especially infant and young children. Our results suggest in some cases of influenza virus infection, the main etiology of AOM is influenza virus.