Can acute Chlamydia pneumoniae respiratory tract infection initiate chronic asthma?

Background: Chlamydia pneumoniae infection can cause acute respiratory illnesses (including sinusitis, bronchitis, and pneumonia) that are sometimes associated with wheezing. Little is known about whether acute infection in a previously unexposed, nonasthmatic individual can produce persistent wheezing leading to a diagnosis of chronic asthma. Objective: We sought to determine whether patients with acute C. pneumoniae respiratory tract infections would develop chronic asthma. Methods: A consecutive series of 163 primary care outpatient adolescents and adults (average age 43, 45% male) who had acute wheezing illnesses or chronic asthma were evaluated for C. pneumoniae infection by serologic testing. A subgroup of these patients also had nasopharyngeal cultures for C. pneumoniae. Results: Twenty patients (12%) were diagnosed with C. pneumoniae infection defined by serology (15), culture isolation (3), or both (2). Of these 20, 10 patients wheezed for the first time and 6 of them subsequently developed chronic asthma (5) or chronic bronchitis (1) along with a serologic profile suggesting chronic infection. The other 10 patients diagnosed with C. pneumoniae infection already had a diagnosis of chronic asthma. In these patients initial serologic findings suggested chronic rather than acute infection. Conclusions: Acute C. pneumoniae respiratory tract infections in previously unexposed, nonasthmatic individuals can result in chronic asthma. Patients previously diagnosed with chronic asthma should be evaluated for possible chronic C. pneumoniae infection.