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Archived Comments for: The burden of non communicable diseases in developing countries

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  1. Infection and cardiovascular disease

    Syed Wamique Yusuf, University of Texas MD Anderson Cancer Center

    27 January 2005

    Dear Sir /Madam

    In the recent paper (1), the authors have elegantly covered the issue of cardiovascular disease in the developing countries. They have have mentioned how cardiovascular disease (CVD) is now an emerging epidemic in developing countries and by year 2010, CVD will be the leading cause of death in the developing countries. They have cited life style changes brought about by industrialization and urbanization in developing countries as a factor and have targeted traditional risk factors like tobacco, alcohol, hypertension and physical inactivity for prevention purposes. Interestingly no mention was made of the association between infection and heart disease. They have failed to mention that prevention of infection, immunization and vaccination against common infections may also be a very important part of preventive cardiology in developing countries.

    Even in developed countries, the prevalence of Chlamydia pneumonia is somewhat higher in Asian population compared to Caucasians (2) and childhood infections are relatively more frequent in South Asians resulting in higher risk of chronic infections, like Hepatitis (3). Infection has been lined with Ischaemic heart disease (IHD) and atherosclerosis (4, 5), and there is a strong association between development of new atherosclerotic lesion and chronic infection (5). In particular the pathogen burden contributes to atherogenesis (4) with Hepatitis A virus being independently predictive of IHD (4). In patients with angiographically normal coronary arteries, infection with multiple pathogens is also an independent determinant of endothelial dysfunction (4). IHD is increasingly being recognized as an inflammatory disease, and both C-reactive protein (CRP) and fibrinogen are significantly elevated in chronic infections (5). There is also a correlation between pathogen burden and CRP levels, with a higher CRP level in patients with a greater pathogen burden (4). Even young otherwise healthy patients with only periodontal disease show evidence of endothelial dysfunction and systemic inflammation (6). Although studies have not shown a conclusive causal link between infection and IHD, it is known that an increase in inflammatory markers are prognostically important, both in healthy population and in patients with IHD (7, 8).

    There is increasing evidence that influenza can trigger coronary and vascular events (9). Influenza vaccination has been associated with about 50% reduction in all-cause mortality in healthy senior citizens, leading the authors to recommend vaccination of all persons over 50 years of age and in all patients with cardiovascular disease (9). Assuming a 50% reduction in cardiovascular death, influenza vaccination could save 91 000 lives per year (9), and influenza vaccination may be one of the most cost-effective interventions for cardiovascular patients (9).

    A lot of these infectious processes could begin in early childhood and by inducing low grade inflammation could manifest or precipitate atherosclerosis at older age. Alternatively an acute infection can generate intense inflammatory response and

    precipitate an acute coronary event. For prevention of growing epidemic of IHD in the developing countries, the authors mention aggressive risk factors management. Perhaps vaccination and preventing infection may be helpful in prevention of atherosclerosis and cardiovascular disease and this aspect of preventive cardiology should be integrated into primary health care.


    1. Boutayeb A, Boutayeb S. The burden on Non Communicable Diseases in developing countries. Int J Equity Health; 2005:4(1):2

    2. Cook PJ, Davies P, Honeybourne D. Chlamydia pneumoniae infection and ethnic origin. Ethn Health 1998; 4:237-46

    3. Aspinall PJ, Jacobson B. Ethnic disparities in health and health care. A focused review of the evidence and selected examples of good practice. (Accessed on 3rdJan 2005)

    4. Prasad A, Zhu J, Halcox JPJ, Waclawiw MA et al. Predisposition to Atherosclerosis by Infections. Role of Endothelial Dysfunction. Circulation. 2002; 106:184-190

    5.Kiechl S, Egger G, Mayr M, Weidermann CJ et al. Chronic infections and risk of carotid atheroscelrosis. Prospective results from a large population study. Circulation 2001; 103:1064-70.

    6.Amar S, Gokce N, Morgan S, Luokideli M et al. Periodontal disease is associated with brachial artery endothelial dysfunction and systemic inflammation. Arterioscler Thromb Vasc Biol 2003; 23:1245-49.

    7.Toss H, Lindahl B, Siebahn A, Wallentin L. For the FRISC Study Group. Prognostic influence of increase fibrinogen and C-reactive protein in unstable coronary artery disease. Circulation 1997; 96:4204-10,

    8. Ridker PM, Cushman M, Stampfer MJ, Tracy RP, Hennekens CH. Inflammation, aspirin and risk of cardiovascular disease in apparently healthy men. N Engl J Med 1997; 336:973-9

    9. Madjid M, Naghavi M, Litovsky S, Ward Casscells S. Influenza and cardiovascular disease: a new opportunity for prevention and the need for further studies. Circulation. 2003; 108:2730-6.

    S.W.Yusuf, M.D M.R.C.P.I

    University of Texas MD Anderson Cancer Center

    Houston, Texas 77030, U.S.A

    Competing interests