Bacterial Endocarditis

After years of dodging bullets and taking on bad guys, the fictitious NYPD Blue character Detective Bobby Simone finally died — after a visit to his dentist. He caught a bacterial infection from an oral treatment in the dentist’s chair, and the germ went straight to his heart. Within a few episodes, Andy Sipowicz had a new partner.

The story may seem incredible, but similar dramas unfold in real life. Simple medical procedures can unleash bacteria in the bloodstream, and the infection can spread to the inner lining of the heart, or endocardium. Doctors call such infections bacterial endocarditis. If not treated, they may cause heart failure or death.

In real life, however, happy endings are the rule. With proper treatment, most people with bacterial endocarditis are quickly cured.

How does bacterial endocarditis occur?

Endocarditis almost always occurs when bacteria get into the blood stream and stick to abnormal heart valves. This is usually due to a preexisting heart condition (such as mitral valve prolapse or thickened valves caused by rheumatic fever) plus a dose of bad luck.

We all get a few germs in our blood every now and then. They can be introduced when we go to the dentist or have simple surgery or suffer a cut. Usually, the bacteria float around harmlessly before being neutralized by the immune system. But some strains of bacteria — mostly members of the streptococcus, enterococcus, or staphylococcus families — manage to use the bloodstream as a passageway to the heart.

The bacteria that can cause endocarditis normally live harmlessly in the mouth, the digestive system, the urinary tract, or the upper airways of the respiratory system. And that’s generally where they’ll stay — unless a medical procedure opens the door to the bloodstream.

Any dental work that makes you bleed, including teeth cleaning, can lead to endocarditis. Other common opportunities for the infection include tonsillectomies, examination with a bronchoscope, prostate or gallbladder surgery, and other operations in the respiratory airways, digestive tract, or urinary tract. People who regularly inject illegal drugs may also introduce bacteria into their blood.

Who gets bacterial endocarditis?

Bacteria hardly ever infect normal, healthy hearts. Practically every person who develops endocarditis already has some significant heart damage. Many have artificial heart valves or valves that are damaged because of an inborn defect or rheumatic fever. People with mitral valve prolapse are also at risk.

What are the symptoms of bacterial endocarditis?

The signs of bacterial endocarditis vary from person to person and can be quite vague. Some people have a flu-like illness with fever, chills, fatigue, and body aches that last weeks or months. Others feel weak or lose weight for no apparent reason. A doctor may suspect bacterial endocarditis after listening to your heart with a stethoscope. The diagnosis is confirmed with blood tests and an echocardiogram, which is an ultrasound view of your heart.

Can bacterial endocarditis be prevented?

If you have any type of heart damage, ask your doctor if you’re vulnerable to bacterial endocarditis. If the answer is yes, you need to protect yourself. Make sure every dentist and physician knows about your condition. Before you undergo any procedure that could cause an infection, the dentist or doctor should give you a dose of antibiotics (most often 2 grams of amoxicillin, or another drug if you have penicillin allergy) to be taken one hour prior to the procedure. Your doctor may give you a card to keep in your wallet that explains your condition.

How is bacterial endocarditis treated?

Once bacteria have set up camp in your heart, you’ll need antibiotics for about four to six weeks. At first, you’ll probably receive the drugs through an IV in the hospital. Later, you should be able to take oral antibiotics at home.

Ideally, your doctor can prescribe a drug that specifically targets your infection. For instance, daily doses of penicillin can wipe out most streptococcus bacteria. Often, however, doctors have to start treating the infection before the germ can be identified. In that case, you’ll be given broad-spectrum antibiotics to attack the most likely bacteria causing the problem.

In most cases, the infection will quickly disappear. Unfortunately, however, many strains of bacteria are developing resistance to antibiotics. Your doctor will want to monitor you closely to make sure the drugs are working. In rare cases, if complications such as heart failure get worse during the antibiotic treatment, you may need surgery to clear up the infection.


Bacterial endocarditis. American Heart Association.

Management of bacterial endocarditis. American Family Physician.

Infective endocarditis. The Merck Manual of Diagnosis and Therapy.

Taubert, Kathryn A. et al. Preventing bacterial endocarditis: American Heart Association guidelines. American Family Physician.

© HealthDay

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