complaints were diagnosed with bronchitis. This resulted in a more frequent use of inhaled steroids and bronchodilators in Dutch children as compared with German children [2].We cannot exclude the fact that a possible geographically heterogeneous worldwide Chlamydia pneumoniae pandemic could contribute to changes in asthma prevalences in different countries. However, it seems unlikely to us that this would be the sole explanation, as not all asthmatics (established or newly diagnosed) have C. pneumoniae present in bronchoalveolar lavage fluid. Moreover, the widespread use of (macrolide) antibiotics has not prevented a clear increase in asthma prevalence. On the contrary, it seems that a decrease in hospitalisation and mortality is strongly associated with an increase in the use of inhaled steroids [3], and there is no indication that this is associated with the use of antibiotics.However, it is certainly worthwhile to pay attention to the socalled Chlamydia-asthma theory proposed by D.L. Hahn and to investigate the presence of Chlamydia pneumoniae or other infectious organisms in new asthma patients.