Beware Strep Infections

The bacteria behind them can cause life-threatening illnesses, doctors warn

FRIDAY, Nov. 12, 2004 (HealthDay News) -- Streptococcus, or "strep" as it's more commonly known, is one of the most familiar medical terms in America. In fact, it's so widely known that some physicians fear the public isn't giving it the attention it deserves.

And that can be dangerous.

Group A streptococcus (GAS) is a sphere-shaped bacterium commonly found in the throat and nose and on the skin of many animals, including horses, pigs, cows and humans. According to the U.S. Centers for Disease Control and Prevention's Division of Bacterial and Mycotic Diseases, people can carry GAS and have no symptoms at all. In fact, most GAS infections are relatively mild illnesses, such as "strep throat" or the skin condition impetigo.

But on some occasions, these bacteria can cause other severe and even life-threatening diseases.

Dr. Kathleen W. Wilson, a New Orleans-based internist, said the problem comes when the body's immune system reacts to a strep infection by forming antibodies.

"These antibodies can attack heart valves, the kidney filtering system and joints," Wilson explained. "That is why antibiotics for strep infection should be used quickly. With rapid antibiotic treatment available, strep complications such as heart valve damage and kidney disease, or glomerulonephritis, are far less common than they were in the last century. But it's important not to get complacent. Strep infections are still serious and require medical attention."

One of the reasons to be particularly alert, Wilson said, is that there's a new variety of strep that can affect soft tissues and cause rapidly progressive tissue destruction and shock.

Two of the most severe, but least common forms of invasive GAS disease are necrotizing fasciitis and streptococcal toxic shock syndrome (STSS). The CDC reports that each year some 10,000 cases of necrotizing faciitis and STSS occur in the United States, with the flesh-eating form about twice as common as the toxic form.

Necrotizing fasciitis, sometimes referred to as "flesh-eating bacteria," destroys muscles, fat and skin tissue, while STSS results in a rapid drop in blood pressure and can cause organs, such as the kidneys, liver and lungs, to fail. (Although the name is similar, STSS is not the same condition as toxic shock syndrome, which is associated with tampon use.)

How serious are these most invasive forms of strep? Very.

About 20 percent of patients who develop necrotizing fasciitis and more than half who develop STSS die of those particularly invasive forms of streptococcal disease, according to CDC figures.

The early symptoms of necrotizing fasciitis include fever, severe pain and redness around a wound or injury site. Early indicators of STSS include fever, dizziness, confusion and a flat, red rash over large areas of the body. Although healthy people can develop invasive GAS disease, those who have chronic illnesses, such as cancer, diabetes and kidney disorders, and those who use steroid medications for a chronic condition have a significantly higher risk.

Wilson pointed out that early treatment with antibiotics remains the most appropriate way to treat strep infections and prevent their deterioration into invasive GAS conditions.

She said any individual with a sore throat or skin infection should be seen promptly by a physician who can perform a laboratory culture to determine whether strep or another bacterium is responsible. If the test results are positive for strep, the current standard of care involves antibiotic administration, with a caution to complete the full course of antibiotics prescribed.

And, reminds the CDC, the spread of all types of strep infections, and other bacterial conditions, can be reduced significantly by the most mundane health measure -- routine hand washing. In particular, thorough hand washing is recommended after coughing and sneezing and before preparing foods or eating.

More information

Information about invasive group A strep is available from the National Institutes of Health.

SOURCES: Kathleen W. Wilson, M.D., New Orleans internist; U.S. Centers for Disease Control and Prevention, Division of Bacterial and Mycotic Diseases, Atlanta
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