Chlamydia trachomatis infection influences the clinical course of acute bronchiolitis.

The frequency of Chlamydia trachomatis infection among young infants admitted with acute bronchiolitis was analysed to determine whether the former affects the clinical course of the latter. A total of 92 infants aged <6 months admitted with acute bronchiolitis were tested for C. trachomatis by a cell culture technique, obtaining nasal smears from each infant's nostrils. A second nasal sampling was taken for respiratory viruses from the study group and tested with real-time polymerase chain reaction. Clinical characteristics of C. trachomatis-positive and -negative cases were compared. C. trachomatis was detected in 22.8% of the infants, mostly as coinfection with respiratory viral agents. Infection with C. trachomatis affected the clinical outcome in acute bronchiolitis and such infants tended to have severe bronchiolitis.