example, country-wide epidemics and the increasing seroprevalence of Chlamydia pneumoniae infection in Finland [4] have been accompanied by corresponding country-wide increased asthma medication use in both males and females and all age groups [5]. The growing body of clinical, epidemiological and therapeutic evidence implicating acute, reactivated and chronic infection by C. pneumoniae in asthma [6,7] forms the basis for proposing the theory that a now waning, geographically heterogeneous worldwide C. pneumoniae pandemic is responsible for the recent unexplained observations.