There have been several articles in the news recently about so called “flesh eating bacteria” and about how the incidence is increasing. Flesh eating bacteria is a popular name for a condition called necrotizing fasciitis. Several different kinds of bacteria can cause this condition, primarily in people who have other risk factors. In this post I will write about the symptoms of necrotizing fasciitis, what kinds of bacteria cause it, where they can be found, who is at risk, and what treatments there are.

What is necrotizing fasciitis?

Necrotizing fasciitis is a soft tissue infection that causes death of the connective tissue around the muscles. This infection typically travels along the connective tissue, which has a poor blood supply, leaving the overlying skin and subcutaneous fat initially unaffected. This can cause a delay in diagnosis and treatment. The infection can rapidly spread and cause a secondary infection of the overlying and underlying skin, soft tissue, and muscle. If not treated quickly it can cause sepsis (blood poisoning) which can rapidly lead to multiple organ failure and death.

How is necrotizing fasciitis treated?

The treatment for necrotizing fasciitis includes both antibiotics and surgery. Prompt administration of intravenous antibiotics limit the spread of infection and surgery is used to remove the dead and infected tissue. Sometimes this can even involve amputation of a limb. Time is of the essence in treatment. Necrotizing fasciitis can progress to death within just a few days.

What causes necrotizing fasciitis?

The most common bacteria that cause necrotizing fasciitis are strep and staph that live on the skin and usually enter the body through a break in the skin such as a cut or scrape.

The organism that has been in the news recently is called vibrio vulnificus, which lives in warm salt water or brackish water. More about this organism shortly.

Vibrio Vulnificus

Vibrio vulnificus lives in salt water or brackish water, usually at a temperature of 68 degrees Fahrenheit or higher. Most infections have occurred on the Gulf coast, but because of increasing warm oceans, it has been found further north, moving north at about a half a mile a year. There have now been vibrio infections documented in North Carolina, Connecticut and New York. This is a rare cause of necrotizing fasciitis, but is increasing in frequency. Infections usually occur when someone wades in contaminated salt water with a cut or scrape on the leg. There is no clue to let you know whether salt water is contaminated or not. It is no less clear than uncontaminated sea water.

What are the risk factors for necrotizing fasciitis?

Anything that compromises the immune system increases the risk of getting necrotizing fasciitis if you are exposed. Here is a list of risk factors:

• Diabetes
• Chronic disease
• Immunosuppressive drugs (eg, prednisolone)
• Malnutrition
• Age > 60 years
• Intravenous drug misuse
• Peripheral vascular disease
• Renal failure
• Underlying malignancy
• Obesity (BMI greater than 30)

If you have none of these risk factors, your chance of getting necrotizing fasciitis, even if exposed is very very low.

What can I do to prevent necrotizing fasciitis from vibrio vulnificus?

Even if you are healthy and have no risk factors, it is not a good idea to wade in salt water at the beach if you have a cut or scrape on a leg or arm. If you do get cut at the beach, get out of the water immediately and wash the cut thoroughly with soap and water. Even though your risk of getting necrotizing fasciitis may be very low, you don’t want to take any chances of getting this life threatening disease.

Certainly if you have any of the risk factors listed above, these precautions are especially important.

Bottom Line

Flesh eating bacteria is a scary name. The news media seize on a name like this because of the shock value. Necrotizing fasciitis, which is the correct term, does not have the same shock value. Nonetheless, this is a very serious and life threatening condition caused by multiple different kinds of bacteria. Healthy people have a very very low risk of getting this condition. Vibrio Vulnificus can cause necrotizing fasciitis and lives in warm salt water or brackish water. You should not wade or swim in the ocean if you have a cut or scrape on your leg or arm, especially if you have any of the risk factors mentioned above.