Hong Kong health officials are investigating three cases of necrotizing fasciitis caused by infection with the waterborne bacterium, Vibrio vulnificus in July.
The details on the cases are as follows:
The first case was an 82-year-old man with underlying chronic illnesses. He presented with fever, right leg pain and swelling on July 1 and was admitted to a public hospital on the same day. The clinical diagnosis was necrotising fasciitis. He was treated with antibiotics and excisional debridement operations were performed. His blood specimen on July 2 yielded Vibrio vulnificus. His condition was stable. He recalled injury to his left index finger by fish fins during food preparation on July 1. His home contacts were asymptomatic.
The second case was a 78-year-old woman with underlying chronic illnesses who lived alone. She developed left foot swelling after sustaining an injury over her left shin in a wet market on July 1. She was admitted to a public hospital on July 2 and above knee amputation of left lower limb was performed on the same day. Her diagnosis was necrotizing fasciitis. She was transferred to the intensive care unit after operation. Her left leg tissue taken on July 2 yielded Vibrio vulnificus. She was treated with antibiotics and her condition was serious.
The third case was a 59-year-old man with good past health. He had left ankle pain and swelling since July 3 and was admitted to a public hospital on July 4. After admission, he developed fever and increasing swelling of left leg with blister formation. The clinical diagnosis was necrotizing fasciitis. He was treated with antibiotics and excisional debridement was performed. Blood culture and left foot necrotic tissue taken on July 4 and 5 respectively grew Vibrio vulnificus. His condition was stable. He recalled injury over his left leg around ten days before onset of symptoms. He had also been to beach and wet market during incubation period. His home contacts were asymptomatic.
So far, no epidemiological linkage has been identified among these three cases. Investigations are on-going.
The Centers for Disease Control and Prevention(CDC) says Vibrio vulnificus is a bacterium in the same family as those that cause cholera and Vibrio parahaemolyticus. It normally lives in warm seawater and is part of a group of vibrios that arecalled “halophilic” because they require salt.
V. vulnificus can cause disease in those who eat contaminated seafood or have an open wound that isexposed to seawater. Among healthy people, ingestion of V. vulnificus can cause vomiting,diarrhea, and abdominal pain. In immunocompromised persons, particularly those with chronic liver disease,V. vulnificuscan infect the bloodstream, causing a severe and life-threatening illness characterized by fever and chills, decreased blood pressure (septic shock), and blistering skin lesions. V. vulnificus bloodstreaminfections are fatal about 50% of the time.
V. vulnificus can cause an infection of the skin when open wounds are exposed to warm seawater; theseinfections may lead to skin breakdown and ulceration. Persons who are immunocompromised are at higher risk for invasion of the organism into the bloodstream and potentially fatal complications.
