Prevalence of antibodies to Chlamydia pneumoniae in a pediatric hospital population in Belgium.

To evaluate the prevalence of antibodies to Chlamydia pneumoniae in a pediatric hospital population, 207 patients admitted to the pediatric unit of the hospital during the period January to April 1989 were screened. A microimmunofluorescence test was used to measure both Chlamydia pneumoniae specific total antibody and IgM antibody. Fifty-eight (28%) patients were found to have antibodies to Chlamydia pneumoniae. Only one serum contained specific IgM. Analysis of the age specific prevalence of antibody showed a sudden rise in the 10 to 12 year old age group. Cross-reaction in the test with the other Chlamydia species is discussed. It is concluded that the incidence of primary Chlamydia pneumoniae infection during the study period was low, but that the infection occurs in Belgium with about the same prevalence as in other countries.