What Is a "Flesh-Eating" Bacterial Infection?
Media reports have popularized the term flesh-eating
bacteria to refer to a very rare but serious bacterial infection known as
necrotizing fasciitis. Necrotizing fasciitis is an infection that starts in the
tissues just below the skin and spreads along the flat layers of tissue (known
as fascia) that separate different layers of soft tissue, such as muscle and
fat. This dangerous infection is most common in the arms, legs, and abdominal
wall and is fatal in 30%-40% of cases.
Quick GuideBacterial Infections 101: Types, Symptoms, and Treatments
Necrotizing fasciitis (flesh-eating disease) facts
- Necrotizing fasciitis refers to a rapidly spreading infection, usually located in fascial planes of connective tissue that results in tissue death (necrosis).
- Different types of bacterial infection can cause necrotizing fasciitis.
- The majority of cases begin with an existing infection, most frequently on an extremity or in a wound.
- Necrotizing fasciitis is a serious condition that is often associated with sepsis and widespread organ failure.
- Treatment of an infection caused by flesh-eating bacteria involves rapid antibiotic administration and/or surgical debridement of the wound areas as well as supportive measures such as insertion of a breathing tube, intravenous administration of fluids, and drugs to support the cardiovascular system.
- Good hygiene and wound care can reduce the chance of developing the disease; necrotizing fasciitis is not usually contagious but it is possible to transmit infectious agents to other people (cross-contaminations of wounds, for example).
- Immunosuppressed individuals (for example, diabetics, elderly, infants, those with liver disease, alcoholics, or those taking immunosuppressive drugs such as chemotherapy for cancer) are at higher risk to develop the disease.
- The prognosis depends on how fast the infection is diagnosed and treated and the patient’s response to treatments; outcomes usually range from fair to poor with complications including tissue loss and or amputation of limbs.
What is necrotizing fasciitis?
Necrotizing fasciitis is a term that describes a disease condition of rapidly spreading infection, usually located in fascial planes of connective tissue that results in tissue necrosis (dead and/or damaged tissue). Fascial planes are bands of connective tissue that surround muscles, nerves, and blood vessels. Fascial planes can bind structures together as well as allow body structures to slide over each other effectively. The disease occurs infrequently, but it can occur in almost any area of the body. Although many cases have been caused by group A beta-hemolytic streptococci (Streptococcus pyogenes), most investigators now agree that many different bacterial genera and species, either alone or together (polymicrobial infections), can cause this disease. Occasionally, mycotic (fungal) species cause necrotizing fasciitis.
Historically, several people described this rapidly advancing condition in the 1840s to 1870s; however, Dr. B. Wilson first termed the condition “necrotizing fasciitis” in 1952. It is likely that the disease had been occurring for many centuries before it was first described in the 1800s. Currently, there are many names that have been used loosely to mean the same disease as necrotizing fasciitis: flesh-eating bacterial infection or flesh-eating disease; suppurative fasciitis; dermal, Meleney, hospital, or Fournier's gangrene; and necrotizing cellulitis. Body regions frequently have the term necrotizing placed before them to describe the initial localization of necrotizing fasciitis (for example, necrotizing colitis, necrotizing arteriolitis), but they all refer to the same disease process in the tissue. Important in understanding necrotizing fasciitis is the fact that whatever the infecting organism(s), once it reaches and grows in connective tissue (fascial planes), the spread of the infection can be so fast (investigators suggest some organisms can progress to involve about 3 centimeters of tissue per hour) that the infection becomes difficult to stop even with both antimicrobial drugs and surgery. Fortunately, this disease is relatively rare; various statistical sources estimate about 500 to 1,500 individuals are reported to have the disease per year in the U.S.
Mortality (death) rates have been reported as high as 75% for necrotizing fasciitis associated with Fournier's (scrotal) gangrene, but the mortality in patients with the infection in other regions of the body (for example, legs or arms) is about 25%. Patients with necrotizing fasciitis have an ongoing medical emergency that often leads to death or disability if it is not promptly and effectively treated.
Picture of necrotizing fasciitis (flesh-eating disease) in the lower leg
Medically Reviewed by a Doctor on 3/17/2016