What seafood lovers need to know about the dangers of the Vibrio bacteria

A man died in Florida earlier this month after eating a contaminated raw oyster. Last week the Centers for Disease Control and Prevention recalled contaminated crab meat imported from Venezuela. What do these two cases have in common? A sometimes deadly infection from a bacteria called Vibrio.

For those who love seafood, this is alarming.

What is Vibrio?

Vibrio is a type of bacteria that thrive in warm, salty water and can be found most often in the Gulf of Mexico and the Atlantic and Pacific Oceans.

There are a few different species that cause illness. Vibrio cholerae is a major concern worldwide and usually strikes because of a lack of clean drinking water. But in the U.S., Vibrio parahaemolyticus and vulnificus are more common. They cause gastrointestinal or skin infections, depending on how you come into contact with the bacteria.

How do people get sick?

Vibrio infections often begin when people eat raw or undercooked seafood: oysters, mussels, clams and scallops, or seafood that was harvested from contaminated water. It usually takes one day to three days to get sick after Vibrio enters the body.

Another way Vibrio enters is through an open cut or scrape.

What are the signs of an infection?

In most healthy people, a Vibrio infection is similar to any stomach bug - after a few days of diarrhea, cramps, nausea and vomiting, they recover without problems.

But other medical issues, like diabetes or liver disease, can make it more serious. People with liver scarring (cirrhosis) were 200 times more likely to die after they consumed contaminated raw oysters, according to one study.

This is because these infections can lead to sepsis, a condition where bacteria enters the blood and plays havoc with your immune system.

In fact, Vibrio vulnificus has a death rate of 30-50 percent if left untreated.

The Vibrio vulnificus species is also more likely to cause skin infections. It could start with severe pain in the affected area, beginning a few hours up to a day after contact. Swelling, redness and worsening pain can develop afterward.

When to seek medical help

Treatment is only needed with signs of sepsis or worsening skin infections, in which case doctors will prescribe antibiotics and fluids.

Signs of sepsis include fever, chills, a fast heart rate or rapid breathing. If it gets to the point where people feel dizzy, confused, or have difficulty breathing, it’s time to call 911.

Worsening skin infections where pain is unbearable, blisters form or the skin darkens in color, are also a medical emergency.

How can you prevent getting sick?

Luckily, for the majority of people, Vibrio seafood poisoning doesn’t always mean a trip to the hospital. Follow these simple precautions to prevent illness.

When to shop for seafood

Go as early as possible in the day - seafood needs to be chilled immediately or else these bacteria are happy to thrive, especially the deadly V. vulnificus. Eating anything that has been unrefrigerated for hours will increase your chances of getting sick.

At the beach, if there are signs of broken seashells in the sand, people should protect their feet. Wearing proper footwear prevents cuts where Vibrio could enter.

And watch out for the little ones - children often have cuts and scrapes, so they shouldn’t enter water. If they do, wash the wound with soap and water and watch closely for any changes.

If anyone does get sick, check in with a doctor, just in case.

Dr. Stephanie Sophie Lee is a pediatrician and preventive medicine resident in South Carolina and a resident in the ABC News Medical Unit.