Seroprevalence of Chlamydia pneumoniae infection in Thailand.

Chlamydia pneumoniae (C. pneumoniae) is an emerging infectious agent, with a spectrum of clinical manifestations, and it has recently been tentatively linked to atherosclerosis. In order to describe the seroprevalence of C. pneumoniae in Thailand, we evaluated 1,798 normal healthy subjects (aged 20-93 years) for anti-C. pneumoniae IgG and IgA. Specific antibodies were measured by the fully automated ELISA method using elementary bodies of C. pneumoniae as an antigen. IgG antibodies against C. pneumoniae were presented in 55.16 per cent of men and 41.63 per cent of women. Anti-C. pneumoniae IgA were presented in 31.50 per cent of men and 27.49 per cent of women. The prevalence of IgG antibody increased with age and reached 78 per cent in subjects between 51-93 years. The pattern of IgA antibody was a saddle shape, which indicated 2 peaks of chronic infection. Our results suggested that C. pneumoniae infection was common in Thailand. The high prevalence of evidence of exposure to C. pneumoniae may have implications for the prevention of cardiovascular disease if further study concludes that infection with this organism is a risk for cardiovascular disease.