Group A Streptococcus: The Flesh-Eater

by Rita Barnes, LPN, CRCST, ACE

Recent newspaper headlines screamed about "flesh-eating bacteria." It sounded like something I needed to get a better understanding about.

The real name is Necrotizing Fasciitis. Pronunciation is neck-row-tie-zing fash-ee-eye-tis. It means "decaying skin." Still sounds very serious and is!

Necrotizing Fasciitis (NF) is a bacterial infection. It may be caused by many different types of bacteria. Group A Streptococcus (Strep Pyogenes) is a common cause of NF and it is this bacterium, Group A Streptococcus (GAS) that is known as the "flesh-eating bacteria." Normally, it is found in the throat and on the skin and causes no symptoms of disease, but they may also cause infections that range from mild to severe and even life-threatening.

The majority of GAS infections are relatively mild illnesses, such as strep throat or impetigo. Occasionally, however, these bacteria can reach parts of the body where bacteria are not usually found, such as the blood, deep muscle and fat tissue, or the lungs, and there they can cause invasive infections. Two of the most severe but least common forms of invasive GAS are necrotizing fasciitis and streptococcal toxic shock syndrome. Necrotizing fasciitis or "flesh-eating bacteria" as the media calls it, is a destructive infection of muscle and fat tissue.

The Group A Strep infection is often secondary to minor trauma or even spontaneous infections that have been reported. Mixed bacterial infection is often secondary to abdominal surgery or perirectal/periurethral infection or trauma.

This scary bacteria is on the Center For Disease Control’s (CDC) emerging infectious diseases list. The condition is on the increase, although data is still being gathered to the increase statistics.

Is this new? No. In 1871, the first description of necrotizing fasciitis was by Joseph Jones when he references more than 2600 cases during the Civil War. Wilson first used the term necrotizing fasciitis; which is the accurate term to describe this disease.

The name "flesh-eating bacteria" is a little sensational, but essentially, the bacteria do indeed eat flesh. They attack the subcutaneous (soft) tissue, which then becomes gangrenous. Infection moves swiftly, usually under the skin, where it is unobservable. Once tissue becomes necrotic (dead), it has to be removed.

Few people who come in contact with a virulent strain of GAS will develop invasive GAS disease; many will have a routine throat or skin infection, and most will have no symptoms at all. Although healthy people can get invasive GAS disease, those with chronic illnesses like cancer, diabetes and kidney disease requiring dialysis and those who use medications such as steroids are at higher risk. In addition, breaks in the skin, like cuts, wounds or chickenpox may provide an opportunity for the bacteria to enter the body.

Approximately 10,000 to 15,000 of invasive GAS disease occurs in the United States each year, resulting in over 2,000 deaths. CDC estimates that 500 to 1,500 cases of necrotizing fasciitis and 2,000 to 3,000 cases of streptococcal toxic shock syndrome occur each year in the United States. Approximately 20% of patients with necrotizing fasciitis die and 60% of patients with streptococcal toxic shock syndrome die. About 10 to 15% of patients with other forms of invasive Group A streptococcal disease die. In contrast, several million persons get strep throat and impetigo annually.

In late 1996, a report in the New England Journal of Medicine stated that children with chickenpox have among the highest risks to invasive group A streptococcal (GAS) disease. Among children younger than 10 years old who have chickenpox, the attack rate for GAS infections was 4.4 per 100,000 cases of chickenpox. Symptoms include:

1. Trauma of some type (however slight)
2. Discomfort in the general region of the trauma
3. Increased pain/tenderness: the pain is out of proportion in relation to the injury
4. Flu-like symptoms: vomiting, diarrhea, dehydration, general malaise, weakness, muscle pain and fever.
5. Swollen tissue or redness: affected area feels hot and very painful
6. Conditions worsen without any improvement of the above conditions
7. Less frequent urination
8. Potential appearance of a sunburn-type rash
9. Large, dark, boil-like blisters may or may not form
10. Possibility of shock

Prompt treatment is essential due to the speed with which the infection spreads. Unfortunately, symptoms resemble the flu and most people delay treatment. Even in a hospital following surgery, many cases may go unrecognized until it is too late. In the early stages, necrotizing fasciitis may be indistinguishable from typical cellulitis.

In addition to the tissue decay, the bacteria causes the rest of the systems to go into systemic shock. This may result in respiratory failure, heart failure, low blood pressure and renal failure. Basically, every system of the body can fail as a result of the severe infection and toxicity of the system.

If diagnosed very early, tissue loss can be ‘relatively" small and surgery would be less severe with removal of flesh, subcutaneous tissue and fat only. The bacteria usually will not attack muscle or bone. In more advanced cases, major limb amputation is necessary. Death from this condition is not uncommon; however, many people are successfully treated.

Group A Streptococcus are spread by direct contact with secretions from the nose and throat of infected persons or by contact with infected wounds or sores on the skin. The risk is the highest when a person is ill, such as with a strep throat or an infected wound. Persons who carry the bacteria but have no symptoms are much less contagious. Treatment of infected persons with an appropriate antibiotic for 24 hours or longer generally eliminates their ability to spread disease. Household items, such as dishes, probably do not play a major role in transmission.

Prevention
The single most important preventative measure is to keep the skin intact. Next is cleanliness. Wash the smallest opening in the skin and apply an antibiotic ointment. Keep a tube handy in the home or at work.

The spread of all types of GAS infections may be reduced by good hand-washing, especially after coughing or sneezing, and before food preparation and eating. People with sore throats should be seen by a doctor who can test for strep. If positive, they should stay at home until 24 hours after starting an antibiotic. Persons with signs of infection—and especially if they have a fever—should seek medical care.

Certainly this is a bacteria to be recognized early—and to be aware of all the signs and symptoms they cause.

References:

• Virginia Department of Health, April, 1996 Fact Sheet
• National Institute of Allergy and Infectious Diseases.
• Center For Disease Control Web site and Polk County Health Department

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