What Is Vibrio Vulnificus (Vibriosis)?

Medically Reviewed by Neha Pathak, MD on August 17, 2023
6 min read

Vibrio vulnificus is a bacteria that can get into your body through open wounds or when you eat uncooked or undercooked shellfish. It leads to a severe condition called vibriosis. This illness can quickly cause sepsis, shock, and blisters that spread and harm your body's tissue.

What are vibrio bacteria?

Vibrio bacteria live in some bodies of water near the coast. There are more of them in these waters between May and October, while the water is warmer. Around 80% of infections happen during these months.

Vibrio vulnificus is a type of vibrio bacterium. It's in the Vibrionaceae family. Other bacteria in this family include V. parahaemolyticus and V. cholerae, which is rare in the United States. Both of these cause stomach issues with severe diarrhea. Vibrio vulnificus, unlike its family members, leads to a very intense infection – even with quick diagnosis and proper treatment.

What is vibriosis?

A few vibrio species can cause you to get sick. When this happens, the illness is called vibriosis. The most common form of vibrio to cause sickness in the Unites States include Vibrio parahaemolyticus, Vibrio alginolyticus, and Vibrio vulnificus.

How often do people get vibrio?

The CDC has found that vibriosis causes around 80,000 illnesses every year in the United States. Out of these, around 52,000 cases are from eating food that or is contaminated with the bacteria. Due to climate change, studies show that the number of infections is expected to rise in the future because of warming waters. This increases the chance for growth of vibrio in a wider area.

Who’s most likely to get vibriosis?

Anybody can get vibriosis. But there are a few groups of people who are at a higher risk. These include people:

  • With weakened immune systems (especially people with chronic liver disease)
  • Who eat raw seafood (especially oysters)
  • Who expose open wounds to salt water or brackish water (water that's more saline than freshwater but less saline than marine waters)







Vibrio has a few causes. It's a good idea to understand what activities can lead to an infection.

Can you get vibrio from swimming?

If you have an open wound or cut and swim in water that has Vibrio vulnificus, you can get infected. The bacteria likes to hang out in water that's warm and slightly salty. This is usually in areas where fresh water meets salty seawater, like rivers.

Can you get vibrio from sushi?

Most people who have this infection get it from eating raw or undercooked shellfish. This tends to happen most with oysters. Sushi typically comes with raw fish, so it's possible to get infected with Vibrio vulnificus from this food.

What foods is vibrio found in?

Vibrio is most often found in raw or lightly cooked oysters; other shellfish like clams, crawfish, crab, mussels, and scallops (especially if they're not properly stored and prepared); or fish that eat oysters (which might have bacteria in their digestive tracts). This is why it's important to cook oysters completely, especially if you're at high risk for vibriosis. Steaming, baking, or frying oysters can help destroy the bacteria. When you prepare fish, cook it to 145 F or until its skin is opaque (you're not able to be see through it).

Do all oysters have vibrio?

Not all oysters have vibrio. But it's hard to tell which ones do. There's no way to know if an oyster is contaminated by the smell, look, or taste of it. An oyster with vibrio looks the same as one without.

Vibrio symptoms can show up in ways based on how you got the infection.

If you ate the bacteria, it could cause:

  • Watery diarrhea
  • Stomach cramping
  • Nausea
  • Vomiting
  • Fever
  • Chills
  • A fast heart rate
  • Confusion
  • Dizziness, fainting, and weakness (which are signs of low blood pressure)

If you get the infection through an open wound, you'll notice a skin infection. This can cause:

  • Rash or skin redness that becomes swollen and painful
  • Fluid-filled, large, painful, and discolored blisters on your skin

How long does it take to get sick after eating bad oysters?

Symptoms tend to show up within 24 hours after you've eaten food with the bacteria.

How serious is vibrio?

Usually, people with a mild form don't have any lasting effects. But in some cases, people with this infection can become severely sick. They may need intensive medical care or have to have an arm or a leg amputated (a surgery to cut it off). Around one in five people with this type of infection die. The infection could become fatal in a day or two of becoming sick.

How long are you sick with vibrio?

A mild case of vibriosis will get better within 3 days.

A vibrio diagnosis can be made by your doctor based on your symptoms and test results. If you show signs of infection and have recently eaten raw or undercooked seafood or been in water with an open wound, they'll want to take a deeper look. They may test for vibrio bacteria in your poop, blood, or in a wound on your body.


Vibrio treatment isn't needed for mild cases. But you should drink a lot of fluids to make up for the liquids you've lost with diarrhea.

There's not much information that suggests antibiotics can make the illness shorter or less intense. But your doctor may give them to you if the bacteria causes an intense or very long illness.


Vibrio complications don't usually tend to be more than diarrhea and vomiting. But some infections (especially those caused by Vibrio vulnificus) can lead to intense complications such as:

  • Bloodstream infections
  • Severe blistering skin lesions
  • Arm or leg amputations

Around 15% to 30% of infections with Vibrio vulnificus are fatal.

If you have symptoms of a Vibrio vulnificus infection, go to an emergency room right away. It's important that you get treatment as soon as possible. Don't wait for the infection to get better. Tell your doctor that you came into contact with seawater or ate raw seafood.


To prevent a vibrio infection, there are many steps you can take:

  • Avoid raw or undercooked oysters or other shellfish. Cook them before you eat them.
  • Don't touch cooked shellfish after you've handled raw shellfish and its juices.
  • Wash your hands with soap and water after you touch raw seafood.
  • Avoid salt water or brackish water if you have a wound or had a recent piercing, tattoo, or surgery.
  • Cover your wounds with a waterproof bandage if you might come into contact with salt water, brackish water, raw seafood, or its juices.
  • Open oysters with gloves on.
  • Wash your cuts and wounds really well with soap and water after they've been around seawater, raw seafood, or its juices.
  • Tell your doctor right away if you get a skin infection, and let them know if you may have come in contact with the bacteria.

If you're at a high risk for vibriosis, make sure you wear clothing and shoes that protect you skin from cuts and scrapes while in salt or brackish water. You should also wear gloves anytime you touch raw seafood.

When you cook shellfish:

  • Throw away any shellfish with open shells.
  • Boil shellfish with shells until the shells open. Then boil them for another 3 to 5 minutes, or add them to a steamer when the water is steaming and cook them for 4 to 9 minutes.
  • Only eat shellfish that open while you cook them, and toss any shellfish that don't open fully after they've been cooked.

When you cook shucked oysters, either fry them in oil for at least 3 minutes at 375  F, boil them for at least 3 minutes, broil them 3 inches from heat for 3 minutes, or bake them at 450 F for 10 minutes.