Abstract
Chlamydia pneumoniae is a worldwide respiratory pathogen involved in 6--20% of community-acquired pneumonias and in about 5% of acute exacerbations of chronic bronchitis. Preliminary data also indicate a possible association between Chlamydia pneumoniae infection and asthma. Further studies are needed to elucidate whether Chlamydia pneumoniae is merely a precipitant of asthma symptoms or is actually one of the causes of asthma.