An oyster that contains Vibrio doesn't look, smell, or taste different from any other oyster. Cooking oysters properly can kill Vibrio and other harmful germs they might contain.
Vibrio pathogens have been sparsely implicated in illnesses in Australia; however, rising sea temperatures and varied weather conditions delivered by climate change could be driving the increased prevalence of these pathogens in our oyster growing regions.
The shell should also be glossy white in color, although a few pink or grey streaks is acceptable. Tap the shell with your finger. The shell should close tightly with no gaps. If the shell does not close, discard the oyster as the animal is likely dead and may harbor bacteria.
But eating raw oysters and other undercooked seafood can put you at risk for infections, including vibriosis, which is caused by certain strains of Vibrio bacteria. Vibrio bacteria naturally inhabit coastal waters where oysters live. Because oysters feed by filtering water, bacteria can concentrate in their tissues.
Potentially life-threatening to most people, symptoms of Vibrio vulnificus infection occurs within 24 to 48 hours of ingestion and may include symptoms such as sudden chills, fever, nausea, vomiting, diarrhea, shock and skin lesions.
Because oysters feed by filtering water, Vibrio and other harmful germs can concentrate in their tissues. When someone eats raw or undercooked oysters, germs that might be in the oyster can cause illness. CDC estimates that about 80,000 people get vibriosis—and 100 people die from it—in the United States every year.
The odds of you being served a dead oyster at a reputable restaurant are just about nil; only the most careless of oyster-shuckers would ever serve one that's dead. Cooking oysters also kills off any pathogens.
What are the symptoms? Infection with Vibrio causes watery diarrhea, stomach cramps, nausea, vomiting, fever, and chills. Symptoms usually begin within 1 to 3 days of ingesting Vibrio. Vibrio can also cause a skin infection when open wounds are exposed to warm seawater.
How common is Vibrio vulnificus infection? Vibrio vulnificus is a rare cause of disease, but it is also underreported. Between 1988 and 2006, the Centers for Disease Control and Prevention (CDC) received reports of more than 900 Vibrio vulnificus infections from the Gulf Coast states, where most cases occur.
What are the signs and symptoms of Vibrio vulnificus infection? Signs and symptoms of Vibrio vulnificus infection can include: Watery diarrhea, often accompanied by stomach cramping, nausea, vomiting, and fever. For bloodstream infection: fever, chills, dangerously low blood pressure, and blistering skin lesions.
Treatment is not necessary in mild cases, but patients should drink plenty of liquids to replace fluids lost through diarrhea. Although there is no evidence that antibiotics decrease the severity or duration of illness, they are sometimes used in severe or prolonged illnesses.
Cooked Oysters
So to once again answer the question, yes, oysters are alive when eaten immediately after being shucked.
How many raw oysters can you eat in a day? You should only consume 3-6 raw oysters in a day. Oysters are nutrient-dense and low in calories; however, they are also high in cholesterol, which can concern some people. Overeating raw oysters has a high risk of food poisoning from Vibrio bacteria.
We can eat oysters all year round, with exceptions. Sydney rock oysters are generally at their peak from September to March. But nature can get in the way. High rainfall can wash undesirable nutrients into estuaries.
Vibrio cholerae live naturally in freshwaters and estuaries. Most strains do not cause human illness. The strains that cause cholera disease (infectious severe watery diarrhoea) are not present in Australian waters. Vibrio parahaemolyticus live naturally in coastal waters.
Vibrio parahaemolyticus
Symptoms usually appear 24 hours after exposure, but can range from 4 hours to 4 days. You may experience: watery diarrhea. abdominal cramps.
Antibiotics can cure a Vibrio vulnificus infection, especially if caught early. Providers use other treatments to keep skin infections from spreading and to treat conditions like shock.
Symptoms usually appear within 12-24 hours and can last 1-7 days. Most people infected with vibriosis will recover on their own; however, severe illness may result in hospitalization or death.
How do people get vibriosis? Most people become infected by eating raw or undercooked shellfish, particularly oysters. Certain Vibrio species can also cause a skin infection when an open wound is exposed to salt water or brackish water.
Seek medical treatment immediately if the person is unable to tolerate oral fluids, if fever is present, if there is blood in the stool, or if other concerning symptoms develop. For all other cases of shellfish poisoning, seek medical treatment as soon as possible.
Just remember that more isn't always better — we'd encourage you to limit your oyster consumption to a maximum of one dozen oysters, two times per week. This will help you avoid any vitamin and mineral toxification risks.
Eating too many oysters on a regular basis can lead to negative health effects, including reduced levels of the minerals iron and copper, which zinc competes for absorption. In addition, people with seafood allergies should also avoid eating oysters.
Shuck your oysters and put them on a grill heated to 450 degrees, either on a baking sheet or shell side down on the grate. Top each oyster with a pat of butter and a sprinkle of chopped herbs (parsley, tarragon, chives, or even cilantro), then close the grill or cover with tin foil.
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.