What are the symptoms of vibriosis?
Most Vibrio infections from oysters result in mild illness, including diarrhea and vomiting. However, people with a Vibrio vulnificus infection can get very sick. As many as 1 in 5 people with a Vibrio vulnificus infection die. This is because Vibrio vulnificus infection can lead to bloodstream infections, severe skin blistering, and limb amputations.
If you develop symptoms of vibriosis, tell your medical provider if you recently ate or touched raw oysters or other raw shellfish or came into contact with salt water or brackish water. Brackish water is a mixture of salt water and fresh water. It is often found where rivers meet the ocean.
Who is more likely to get vibriosis?
Anyone can get vibriosis, but you may be more likely to get an infection or severe illness if you:
- Have liver disease, cancer, diabetes, HIV, or the blood disorder thalassemia
- Receive immune-suppressing therapy for the treatment of disease
- Take medicine to lower stomach acid levels
- Have had recent stomach surgery
- Are 65 years or older
How do people get vibriosis?
Most people become infected by eating raw or undercooked shellfish, particularly oysters. Some people become infected by:
- Getting brackish or salt water in a wound, such as when swimming, wading, or fishing.
- Cutting themselves on an item, such as a rock or pier, that has come into contact with brackish or salt water.
- Getting raw seafood juices or drippings in a wound.
How can I stay safe?
Follow these tips to reduce your chances of getting an infection when eating or touching shellfish and other seafood:
- Don’t eat raw or undercooked oysters or other shellfish.
Fully cook them before eating, and only order fully cooked oysters at restaurants. Hot sauce and lemon juice don’t kill Vibrio bacteria and neither does alcohol.
- Some oysters are treated for safety after they are harvested. This treatment can reduce levels of Vibrio in oysters, but it does not remove all harmful germs.
- Separate cooked seafood from raw seafood and its juices to avoid cross contamination.
- Wash your hands with soap and water after handling raw seafood.
- Stay out of salt water and brackish water if you have a wound (including from a recent surgery, piercing, or
tattoo).
- Cover any wounds if they could touch raw seafood or raw seafood juices, or if you might come into contact with brackish or salt water.
- Wash open wounds and cuts thoroughly with soap and water if they contacted salt water, brackish water, raw seafood, or raw seafood juices or drippings.
What are tips for cooking shellfish?
Before cooking, discard any shellfish with open shells.
For shellfish in the shell, either:
- Boil until the shells open and continue boiling another 3–5 minutes, or
- Add to a steamer when water is already steaming and cook for 4–9 minutes.
Only eat shellfish that open during cooking. Throw out any shellfish that do not open fully after cooking.
For shucked oysters, either:
- Boil for at least 3 minutes
- Fry in oil for at least 3 minutes at 375°F
- Broil 3 inches from heat for 3 minutes, or
- Bake at 450°F for 10 minutes
Grab some fluids and put your doctor on speed-dial
A dozen raw oysters can seem like the most luxurious way to start a meal. Unfortunately, one bad oyster can get you so sick you’ll be out of commission for days. Food poisoning from oysters is somewhat rare, but if it gets you, it’s important to monitor your health closely for at least three days, especially if you have other health complications.
An oyster can be infected with several pathogens than can cause illness, the most common being norovirus and vibriosis. Since shellfish filter seawater through their bodies to find food particles, pathogens can seep into the oysters and infect them. According to the Centers for Disease Control and Prevention, norovirus is the leading cause of food poisoning in the United States, and it can affect raw or cooked food that has been handled by someone infected with the virus. Oysters and other bivalve shellfish can contract norovirus-causing pathogens even before they’re handled by humans, as the water the seafood live in can be contaminated with untreated human sewage (causing norovirus) or bacteria naturally occurring in warm water (like vibrio, which causes vibriosis).
Vibrio bacteria live in warm seawater, and are rarer pathogens, but can be more serious. As water warms, vibro can rapidly multiply, potentially infecting a larger number of oysters. To avoid vibrosis, the CDC recommends cooking oysters to a bacteria-killing temperature by frying them in oil for at least three minutes at 375°F, broiling them three inches from heat for three minutes, or baking them at 450°F for 10 minutes. The Washington State Department of Health recommends taking the temperature of cooked oysters to ensure they’ve been cooked all the way through, registering an internal temperature of 145°F. Cooking oysters reduces your chance of getting sick from the seafood, but unfortunately is not 100 percent effective.
Even if you’ve done the best you can to ensure that the oysters you’re eating are safe, there’s still a chance you can get a bad one. If you do get sick, the best thing to do is drink lots of water to replace the fluids lost during illness to prevent dehydration. While you’re chugging water, call your doctor or local medical clinic, or take a stroll to the hospital. You’ll probably be fine in two or three days, but since some forms of seafood-borne food poisoning can be extremely serious, it’s important to get professionals involved as the illness may require more medical care.
In the throes of vomiting, diarrhea, and stomach pain, you may not be thinking about other people, which makes sense. However, wouldn’t it be great if you could help others avoid feeling as awful as you do right now? Exactly. To do this, contact your local health department. Even though it may be the last thing on your mind, you or someone you know should get in touch with the health department to let them know someone in their area has gotten sick from oysters. Since contamination often occurs from the area the oysters are harvested, the health department can work on closing the potentially contaminated fishing areas, as well as investigate the health practices at the restaurant you purchased the oysters.