Helicobacter pylori, Chlamydia pneumoniae, and cytomegalovirus: chronic infections and coronary heart disease.

We conducted a MEDLINE search of the English-language literature from 1966-1999 on the association of chronic infections with Helicobacter pylori, Chlamydia pneumoniae, and cytomegalovirus (CMV) with coronary heart disease (CHD); additional literature was retrieved from references of selected articles. All human studies were included. Abstracts were excluded because of limited data. Chronic infections in CHD are speculated to be due to serum antibody concentrations of one or more of the three organisms. Data for H. pylori and CMV are difficult to interpret due to the confounding factor of childhood poverty and studies conducted in transplant recipients, respectively. Chlamydia pneumoniae data appear stronger with elevated IgG antibody titers (> or = 64) as a risk factor. Larger prospective studies are warranted to determine an association with CHD before universal prophylaxis or treatment of these chronic infections.