A seroepidemiological study of Mycoplasma pneumoniae infections in Denmark over the 50-year period 1946-1995.

The epidemiological pattern of Mycoplasma pneumoniae infections in Denmark over the 50-year period 1946-1995 is described. The study is based on blood specimens received at the central laboratory at Statens Serum Institut for titration of cold agglutinins (CA), initially for the diagnosis of CA positive primary atypical pneumonia, and during the 1960s of M. pneumoniae infection; in addition, specimens from the last 38 years were tested for antibodies specific to M. pneumoniae. By retrospective analysis of the test results compiled over the years it was found that intervals of regular periodicity have been interrupted by an era of changes in the pattern. Attention is paid to the significance of CA for this study, and the possible background of the epidemiological pattern is described.