Tuesday, July 17, 2012

Raw Shellfish and the Risk Associated with Vibrio vulnificus

This news report, submitted by our colleague Larry Grunden, shows the potential danger of infection associated with eating raw clams and oysters. In this report, a 61 year old woman suffered a life threatening Vibrio vulnificus infection after eating raw clams two year ago. She survived, but did need to have her leg amputated, and nearly lost one of her arms. (The attached news report is incorrect in calling this a virus).

Vibrio vulnificus is a gram negative bacterium found in warm seawater. In healthy people, it can cause gastroenteritis (vomiting, diarrhea, and abdominal pain), but in people with an underlying health issue, particularly chronic liver disease, it cause infection of the bloodstream (septicemia). In these cases, it has a high mortality rate (~50%). The organism is highly invasive and produces toxins (a cytolysin, a hemolysin, and a thermolysin).

A few other notes:
- Hot sauce will not kill the organism.
- Consumption of liquor will not help either, in fact, those who drink too much of this type of sauce will be more susceptible.
- Other pathogens associated with raw clams and oysters that are also naturally found in seawater – other members of the Vibrio family (Vibrio parahaemolyticus, Vibrio cholerae - causative agent for cholera, and other vibrio species), Aeromonas, and Plesiomonas.
- Enteric pathogens associated with shellfish contamination - the viruses norovirus and Hepatitis A as well as bacterial pathogens Shigella, Salmonella, Campylobacter, and E. coli.
- Water testing done for the safety of harvesting water normally uses indicators associated with fecal contamination. This is good for the enteric pathogens, but not good for the pathogens such as Vibrio that are naturally found in seawater.
- The risk of Vibrio vulnificus contamination increases in the warmer months (due to warmer ocean waters).

Key message – there is a risk when consuming raw oysters and clams, and this risk is greatly magnified for those with underlying health issues such as immunosuppression or advanced age, and especially chronic liver disease.

Flesh-eating virus nearly cost woman her life

Lewisberry woman got bacteria from clams

A York County woman nearly died from a flesh-eating bacteria she came in contact with about two years ago.

Maureen Horan, 61, known to her friends as "Mo," said she almost didn't survive her ordeal.
Her near-death ordeal began on the last day of a 2010 during a vacation to the Jersey Shore. Horan and her husband, Dennis, had a late lunch. Horan's meal included raw clams.

"I knew there was something wrong when I swallowed the one clam, but it was too late," Horan said.

By the next day Horan said she was in severe pain. She went to the emergency came home, but her condition only got worse.

"I get up and the pain is worse. My toes are black, my arm is red, my leg is red and my sister-in-law said, "I don't know what it is, but you make them admit her," Horan said.

Horan was eventually flown to Penn State Hershey with the infection spreading rapidly. She said she was at greater risk because of a liver condition.

Doctors said the clam Horan ingested was contaminated with a bacteria that lives in warm seawater and on raw shellfish. It's called Vibrio vilnificus. The rare virus produces a toxin which kills tissue -- a type of flesh eating bacteria.

Orthopedic surgeon Spence Reid was among a team of surgeons who took care of Horan. Reid amputated Horan's left leg, far above the knee to remove the dead tissue and stop the spread of the infection, but doctors were able to save her left arm. Reid said his patient beat the odds.

"Fifty percent of the people who come in like she did, die within the first 48 hours of getting the infection. So, yeah, she was pretty lucky," Reid said.

"They said, 'It's your leg or your life,' and you choose life," Horan said.

Horan now has a computerized prosthetic leg, a brand called C-leg, and a large scar on her arm.

"That's the most beautiful scar in the world because I have it," Horan said of the scar on the arm doctors were able to save.
Horan said she has always been very active with horseback riding and skiing. She said she is hoping to do more, including walking her beloved dog, Petey.

She is undergoing physical therapy to learn how to perfect everyday activities. She said using a prosthetic expends a lot of energy.

"It is tough when I leave here. I'm pretty well wiped out," Horan said.

 Horan said she appreciates what she has, not what she doesn't have.

Horan said one thing she will never do, on any day, is eat raw seafood.

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