Respiratory Chlamydial infections in a Hong Kong teaching hospital and association with coronary heart disease.

The microimmunofluorescence antibody technique was used to determine the seroprevalence of antibodies to Chlamydia pneumoniae and Chlamydia psittaci from hospitalized patients in Hong Kong. Antibodies to C. pneumoniae were found in 54.8% of 157 patients hospitalized with respiratory disease, in 71.1% of 83 patients with cardiac disease and in 31.2% of 93 patients without either respiratory or cardiac disease. Antibodies to C. psittaci were found in 0.9% of the combined study groups. There was serological evidence of C. pneumoniae being the responsible agent in 24.8% of the severe respiratory cases. A significant correlation between antibody prevalence and coronary heart disease was identified during the study.