Asthma and Atypical Bacterial Infections: Chlamydia pneumoniae, Mycoplasma pneumoniae and Legionella pneumophila

Background: Respiratory infections with M. pneumoniae and C. pneumoniae are well-defined causes of acute exacerbation of asthma. This study was undertaken to investigate the association between infections with these pathogens, as well as L. pneumophila, and expression of asthma symptoms.

Materials and Methods: A single throat swab specimen was taken from 72 asthma patients (39 presented with an acute exacerbation and 33 had stable asthma) and 46 controls. Bacterial infection with C. pneumoniae, L. pneumophila, and M. pneumoniae were detected by polymerase chain reaction (PCR).

Results: C. pneumoniae infection was related with exacerbation of symptoms in asthmatic patients (23% in asthma exacerbation, 3-3% in stable asthma, 2.2% in controls).pneumophila infection was higher in asthmatic group than in the control group (5.5% vs 0%). M. pneumoniae infection was not associated with asthma (7% vs 4.3%). There was a statistically significant positive correlation between asthma severity and PCR positivity, a finding that is consistent with the dose-response relationship and may be considered as a positive evidence for the causality of association.
 

Conclusions: C. pneumoniae infection should be sought in an acute asthma attack and especially if the patient has severe asthma, and ampirical antibiotic treatment may be considered.