Vibrio vulnificus

Vibrio vulnificus is a bacterium which normally lives in warm seawater and can cause disease in people who eat contaminated seafood or those who have an open wound that is exposed to seawater. V vulnificus infection is relatively rare, but probably under-reported.

Clinical features

Ingestion of contaminated seafood

Raw oysters are most commonly implicated in transmission of V vulnificus. In healthy people, ingestion of contaminated seafood can cause vomiting, diarrhoea, and abdominal pain. In people with impaired immunity, particularly those with chronic liver disease or diabetes mellitus, V vulnificus can infect the bloodstream (septicaemia). This results in widespread haemorrhagic bullae (large blood-filled blisters) with fever and chills, and decreased blood pressure (septic shock). This condition is fatal in about 50% of patients.

Exposure of open wounds to seawater

Skin infection can result when open wounds are exposed to warm seawater. Wounds may be pre-existing or obtained in the water, e.g. from crabs, coral, or fishhooks. These infections may lead to cellulitis, necrosis (tissue death), haemorrhagic bullae, and infection of the bloodstream, particularly in people with impaired immunity.

Diagnosis

V vulnificus infection is diagnosed by stool, wound, or blood cultures using a special growth medium.

Treatment

Antibiotic therapy with doxycycline and a third-generation cephalosporin (e.g. ceftazidime) is generally recommended. Children can be treated with trimethoprim-sulfamethoxazole plus an aminoglycoside.

Necrotic tissue should be surgically removed. In contaminated wounds involving the limbs, amputation is sometimes necessary.