Infection may be at the root of heart disease and more…

Everyone gets infections from time to time—a swollen cut…a tooth abscess…or simply a common cold. Most infections come on quickly, cause a brief period of discomfort and then disappear, either on their own or with medication.

What research is now finding: The acute illnesses that we get from infections might be just the tip of the iceberg. Experts now believe that some of the most serious chronic diseases are actually old infections in disguise.


If you’re struck with a nasty infection, you probably assume that once you start feeling better, everything is fine. But that may not be true. Even after your symptoms are gone, some bacteria and viruses have the ability to linger almost indefinitely—you can have a subclinical infection that persists months or even years after the initial illness is gone.


Some infections, such as those caused by the human papillomavirus (discussed below), have a proven link to chronic diseases. Others may be part of a constellation of risk factors that may also include genetics or immune system vulnerabilities. Examples…

• Atherosclerosis. Up to half of those with atherosclerosis (the accumulation of cholesterol and other fats on artery walls) have none of the usual risk factors, such as smoking or high blood pressure. Yet something causes the fats to accumulate.

Arterial inflammation is a known trigger for atherosclerosis—and inflammation is often due to infection. When researchers examined the blood vessels of patients with atherosclerosis, they repeatedly discovered Chlamydophila pneumoniae (a bacterium that causes pneumonia and bronchitis), Helicobacter pylori (a bacterium that causes ulcers) and other infection-causing organisms. This doesn’t prove that the organisms were responsible for the atherosclerosis. Some bacteria or viruses may have been innocent bystanders that just happened to be there.

What’s more, if the microbes caused atherosclerosis, eliminating them should have been helpful—but heart attack patients who were treated with antibiotics were just as likely to have a second heart attack as those who weren’t given the drugs. It’s possible, however, that the bacteria were eliminated after the arterial damage was done.

What is known: It’s been proven that patients with periodontal disease (a gum infection) are more likely to get heart disease. So are people with high levels of C-reactive protein (CRP), an inflammatory “marker” that may be elevated by any type of infection.  

My advice: Since CRP is a heart disease risk factor—one that may be caused by infection—it’s worth getting it checked. Ask your doctor for advice on the frequency of CRP testing. People who test high might be motivated to take better care of themselves—stopping smoking, eating a healthier diet, lowering blood pressure, etc. Be sure to get regular dental checkups, too.

Also helpful: If you have been diagnosed at any time with C. pneumoniae, H. pylori or another serious infection, tell your doctor so that he/she can consider this as a potential risk factor for atherosclerosis.

• Rheumatoid arthritis. It occurs when the immune system attacks the membrane that lines the joints, usually in the hands and feet. Periodontal disease appears to increase risk for rheumatoid arthritis.

What may happen: One of the bacteria (Porphyromonas gingivalis) that causes virtually all periodontal disease produces enzymes that allow the infection to survive in crevices between the teeth and gums. These enzymes then trigger a chemical reaction that produces immunogens, molecules that activate an immune response in the body’s joints.

Scientific evidence: A study of more than 6,600 men and women found that those with moderate-to-severe periodontitis were more than twice as likely to have rheumatoid arthritis as those with no or only mild periodontitis.

Even though not everyone with periodontal disease will develop rheumatoid arthritis (or have worse symptoms if they’ve already been diagnosed), there’s strong evidence that the two are related.

My advice: In addition to daily brushing and flossing, get your teeth checked at least once a year. Periodontal disease can be treated with professional care. It will help you save your teeth—and possibly your joints as well.

• Cervical and anal cancers. Virtually all of these malignancies—along with many cancers of the oral cavity—are caused by the human papillomavirus (HPV), the most common sexually transmitted infection in the US.

HPV is so common that most sexually active men and women will get at least one form of the virus. Most people will never know they’re infected (your immune system usually eliminates the virus with time), and there’s no blood test to detect it. Most HPV viruses have oncogenic (cancer-causing) potential. Two of the highest-risk strains, types 16 and 18, account for the majority of cervical cancers. (The viruses that cause genital warts do not cause cancer.)

My advice: The HPV vaccine is recommended for young men and women before they start having sex, but it’s effective for anyone who hasn’t yet been exposed. Even if you’ve already been infected with HPV, the vaccine may protect you against a strain that you haven’t yet been exposed to. Talk to your doctor for advice.

Also important: Women between the ages of 21 and 29 should have a Pap test every three years, and starting at age 30, they should have a Pap and HPV test at least every five years until age 65. (The HPV test may detect the virus before cell changes can be seen with the Pap test.) A form of the Pap test can also be done for men and women who engage in anal sex.