Cardiovascular disease: an infectious aetiology?

Cardiovascular disease is currently the most common cause of death in the developed world and is increasing in incidence in developing countries. High blood pressure, smoking and high levels of cholesterol are the primary risk factors for cardiovascular disease. While these and other risk factors account for the majority of the aetiology and epidemiology of cardiovascular disease, they cannot account for the entirety. In recent years there has been a resurgence of interest in the role that infectious agents, in particular Chlamydia pneumoniae, Helicobacter pylori and cytomegalovirus, play in the pathogenesis and epidemiology of cardiovascular disease. Epidemiological, clinical and animal studies have shown a link between infection with these organisms and coronary heart disease, myocardial infarction and stroke. Infection alone is unlikely to lead directly to cardiovascular disease; however, it could, in association with other risk factors, initiate or exacerbate the development of atherosclerotic plaques. This review discusses the research which has implicated C. pneumoniae, H. pylori and cytomegalovirus infection as risk factors for cardiovascular disease and the possible mechanisms by which infection can influence atherogenesis.