Diagnosis of Chlamydia pneumoniae in community-acquired pneumonia in children in Chile

The incidence of Chlamydia pneumoniae in community-acquired pneumonia in ch ildren was studied prospectively in 112 children aged 1 mo to 14 y. Diagnos is of C. pneumoniae was performed by polymerase chain reaction (PCR) on nas opharyngeal aspirates and serology by the microimmunofluorescence test on a single serum specimen. Three (2.7%) cases of pneumonia due to this agent w ere diagnosed by bath PCR and serology. C, pneumoniae was not found in any of 62 children below 5 y of age. In the age group 5-8 y, only 1/30 (3%) was found positive, and in the age group 9-14 y, C. pneumoniae was diagnosed i n 2/20 (10%) children. Conclusion: Although the number of enrolled patients is small, and the diag nostic techniques used may have some limitations, the results of this study suggest that C. pneumoniae plays a minor role in the aetiology of pneumoni a in children less than 9 y of age in our country. However, it should be co nsidered as a. potential agent in pneumonia in older children.