Vibrio vulnificus (V. vulnificus) is a kind of bacteria that normally lives in warm seawater. It may cause infection in those who have an open wound exposed to seawater or in those who eat seafood contaminated with the bacteria.
Wound infection with V. vulnificus may result in necrotising fasciitis (commonly known as "flesh-eating disease"), which is a serious bacterial infection of the soft tissue and fascia (a sheath of tissue covering the muscle). It can lead to tissue destruction and can be fatal. The mortality rate of persons affected by V. vulnificus associated necrotising fasciitis is about 30% locally. Most cases of infection were reported during summer.
Clinical features of necrotising fasciitis may include intense pain, redness, swelling and rapidly developing tissue destruction. The skin changes can start at the site of injury as trivial as a small cut or bruise, while in other cases there is no obvious source of infection. The level of pain is out of proportion to the visible skin changes.
Consuming food that is contaminated with V. vulnificus may occasionally cause diarrhoea, vomiting and abdominal pain. In persons with underlying medical conditions, especially liver diseases, V. vulnificus can infect the bloodstream typically causing fever, chills, decreased blood pressure and blistering skin lesions.
Mode of transmission
V. vulnificus infection is acquired from exposure of wounds or soft tissues to the germ that is present in seawater or seafood, or through eating raw or undercooked shellfish, particularly oysters harvested from warm water. There is no evidence of human to human transmission.
High risk groups
All persons can be affected. People who come in direct contact or handle raw seafood have a higher risk of necrotising fasciitis. Persons with underlying medical conditions, such as diabetes mellitus, cancer, kidney diseases, heart diseases, chronic liver diseases, or those with impaired immune response may also be at increased risk of serious complications.
Usually 24 – 72 hours
Appropriate antibiotics given promptly are needed to kill the germ. For necrotising fasciitis, in order to stop infection from spreading, surgery, e.g. removal of dead tissue or amputation of the limb, may be required. Some patients may require intensive care.
Some tips for preventing V. vulnificus infection, particularly among people with impaired immune response or with underlying medical illnesses include:
- Avoid having the wound coming in contact with seawater or raw seafood.
- Cleanse the wound thoroughly and cover it properly with waterproof dressing. Prompt first aid care of even minor, non-infected wounds.
- Avoid skin contact with dirty water when visiting a wet market.
- Be careful with sharp parts of seafood, such as fish fins, shrimp heads and crabs to prevent cuts.
- Wear thick rubber gloves when handling raw shellfish or other seafood.
- Avoid eating raw oysters or shellfish.
- Cook seafood thoroughly; for shellfish (e.g. oysters, clams, mussels), cook until the shells open.
- Avoid mixing ready-to-eat food and raw seafood.
Patients should seek medical advice promptly if they develop symptoms and signs of infection such as increasing redness, swelling and pain on the skin.