Seroprevalence of Chlamydia pneumoniae infection in Taiwan.

OBJECTIVES: To survey the seroprevalence of Chlamydia pneumoniae (C. pneumoniae) infection in healthy subjects in Taiwan. MATERIALS AND METHODS: We used microimmunofluorescence antibody assay to survey the prevalence of antibodies to C. pneumoniae in 620 serum samples from healthy subjects aged 6 months to 86 years in Taiwan. RESULTS: The mean prevalence (+/-SD) of IgG antibodies against C. pneumoniae at titer greater than or equal 1:16 was 55.8% (range 7.8-81.8%). The antibody prevalence was low in children under the age of 10 years (7.8%), and increased rapidly with age. Most individual acquired infection during the second and third decades of life with highest antibody prevalence reached up to 81.8% at fifth decade of life and remained high (70%) thereafter. CONCLUSIONS: Chlamydia pneumoniae infection is highly endemic in Taiwan. These data contribute to the understanding of asymptomatic infections with C. pneumoniae in general population and should serve as a basis for studies on the role of C. pneumoniae infections and their related diseases.