Necrotising Fasciitis

Causative agent

Necrotising fasciitis (commonly known as "flesh-eating infection") can be caused by more than one type of bacteria. These include Group A Streptococcus, Vibrio vulnificus, Klebsiella, Clostridium, Escherichia coli, Staphylococcus aureus and Aeromonas hydrophila. Group A Streptococcus  is considered the most common cause of necrotising fasciitis.

Clinical features

Necrotising fasciitis is a serious bacterial infection of the soft tissue and fascia (a sheath of tissue covering the muscle). The infection spreads along fascial planes and leads to tissue destruction and sometimes limb loss. Severe cases can be fatal.

Patients with necrotising fasciitis may complain of pain or soreness of a limb or the trunk. The skin may be warm with a reddish swelling that spreads rapidly. There may be ulcers, blisters or black spots on the skin. The level of pain may be out of proportion to the visible skin changes. The patient may also experience fever, chills, fatigue or vomiting.

Mode of transmission

The bacteria that cause necrotising fasciitis most commonly enter the body through a wound in the skin, such as a cut, scrape, burn, insect bite, puncture wound or surgical wound. Besides, necrotising fasciitis caused by Vibrio vulnificus can also be acquired through eating raw or undercooked seafood, such as oysters, harvested from warm waters.

Necrotising fasciitis rarely spreads from person to person.

High risk groups

All people can be affected by necrotising fasciitis. People who frequently handle or have direct contact with raw seafood have a higher risk of acquiring necrotising fasciitis associated with Vibrio vulnificus infection. People with underlying medical conditions that weaken their immune system, such as diabetes mellitus, cancer, kidney diseases and liver cirrhosis, are also at increased risk of acquiring the infection.

Incubation period

The symptoms often start within hours after an injury.

Management

Appropriate antibiotics given promptly are needed to kill the bacteria. In order to stop the infection from spreading, surgery, e.g. removal of the dead tissue or amputation of the limb, may be required. Some patients may require intensive care.

Prevention

To prevent the infection, members of the public should maintain good personal hygiene and practice good wound care:

Maintain good personal hygiene

• Perform hand hygiene frequently. Wash hands with liquid soap and water, and rub for at least 20 seconds. Then rinse with water and dry with a disposable paper towel or hand dryer. If hand washing facilities are not available, or when hands are not visibly soiled, hand hygiene with 70 to 80% alcohol-based handrub is an effective alternative.

Proper wound management

• Clean wounds immediately and cover properly with waterproof adhesive dressings until healed.
• Prompt first aid care of even minor, non-infected wounds.
• Perform hand hygiene before and after touching wounds.
• Consult doctor promptly if symptoms of infection develop, such as increasing redness, swelling and pain on the skin.
• Avoid going to swimming pools, other water facilities or natural bodies of water, e.g. rivers, lakes and oceans, if you have an open wound.

Wear protective gloves when handling raw shellfish or other seafood.

For details of necrotising fasciitis caused by Vibrio vulnificus, please refer to the fact sheet of Vibrio vulnificus infection.