Prevalence of Chlamydia pneumoniae in acute respiratory tract infection and detection of anti-Chlamydia pneumoniae-specific IgE in Japanese children with reactive airway disease.

We examined the prevalence of Chlamydia pneumoniae in acute respiratory tract infection and association of C. pneumoniae infection and reactive airway disease in Japanese children. Four hundred eleven children with acute respiratory tract infection were enrolled in this study, and C. pneumoniae was isolated from 58 (14.1%) patients by culture. Evidence of infection with C. pneumoniae was detected in 58 children with pneumonia (34.5%), bronchitis (41.4%) and upper respiratory tract infection (24.1%). Twenty-nine (50.0%) out of 58 patients were younger than 5 years old and 18 (31.0%) had wheezing at first visit. A logistic test for anti-C. pneumoniae-specific IgE showed the deference in the fluorescence unit between the patients with C. pneumoniae infection with and without wheezing was statistically significant (Po = 0.02748, to = 2.31891). In conclusion, C. pneumoniae seems to be an important respiratory tract pathogen among young Japanese children, and our results support the association of C. pneumoniae infection and reactive airway disease.