Raw oysters are delicious and nutritious, making them a favorite dish for many people. However, this type of food carries the risk of infection from Vibrio bacteria, which can attack you as soon as they enter your body.
Vibrio vulnificus is a motile, gram-negative bacterium. It is one of the many species of Vibrio (which includes several pathogenic species known to infect humans, the most famous being Vibrio cholerae and Vibrio parahaemolyticus, responsible for acute gastrointestinal infections characterized by severe diarrhea) belonging to the family Vibrionaceae. Vibrio vulnificus is commonly found in warm coastal waters and thrives when water temperatures are above 20°C. It is not related to pollution. In addition to causing necrotizing fasciitis, Vibrio vulnificus can lead to very severe systemic infections when consuming contaminated seafood that has not been properly cooked (including shrimp, fish, clams, and especially raw oysters), with an average mortality rate that can reach up to 50%.
According to the FDA, Vibrio vulnificus bacteria typically cause gastrointestinal symptoms such as diarrhea, vomiting, and abdominal pain. However, individuals with medical conditions such as liver disease, diabetes, stomach disorders, or other conditions that compromise the immune system can experience rapid immune system deterioration, leading to serious complications and even death. Anyone with these health issues who contracts Vibrio should see a doctor as soon as possible.
A 71-year-old man in the US died after eating raw oysters.
Earlier this year, a woman from Texas also died after eating raw oysters. While on vacation in Louisiana, Jeannette LeBlanc, along with friends and family, collected some shellfish and ate them. A few days later, she experienced difficulty breathing, and her ulcers and rashes worsened significantly. Upon arriving at the hospital, she was diagnosed with a bacterial infection caused by Vibrio. LeBlanc battled this illness for three weeks but ultimately succumbed to the infection.
Due to the nature of the ulcers caused by Vibrio infections, this bacterium is often referred to as “flesh-eating bacteria.” However, according to the CDC, the diseases caused by Vibriosis are distinct from the necrotizing fasciitis commonly referred to as “flesh-eating infections,” which are caused by group A strep, E. coli, and staphylococcus.
Also according to the CDC, approximately 80,000 people get sick from Vibrio bacteria each year, with around 100 of these cases resulting in death. It is estimated that about 52,000 of these cases are due to consuming contaminated food, primarily raw or undercooked shellfish.
Each year, approximately 80,000 people fall ill due to Vibrio bacteria, with around 100 of these cases resulting in death.
Why are oysters infected with Vibrio? Oysters feed by filtering water. If the water is contaminated, the oysters can also become infected. There are about 12 species of Vibrio that live in saltwater or brackish water that oysters may come into contact with.
Not only can eating oysters pose a risk, but swimming in saltwater that is contaminated with Vibrio while having an open wound also significantly increases the risk of bacterial infection. Dr. Gabby Barbarite (a Vibrio researcher at the Oceanographic Institute, Florida Atlantic University) shared with Health: “The term ‘flesh-eating bacteria’ may make you think that if you touch them, your skin will rot away to the meat. But that’s not true. You must have a cut or an existing open wound. Or you need to eat infected raw seafood for them to have the chance to enter your bloodstream and break through your healthy skin.“
Not only eating oysters, but swimming in contaminated saltwater with an open wound also significantly increases the risk of bacterial infection.
In reality, we can protect our health by consuming cooked oysters. However, raw oysters are currently a delicacy, which inadvertently leads to unwanted health risks such as being attacked by flesh-eating bacteria.
According to the FDA, cooking temperatures are the only way to kill Vibrio bacteria, hence the recommendation for everyone to eat cooked oysters to avoid health risks. Consuming raw oysters is also a primary culprit in the spread of Hepatitis A and norovirus, commonly known as stomach flu. Both infections can cause nausea, vomiting, and abdominal pain.
How to Avoid Flesh-Eating Bacteria: Safe Ways to Eat Oysters
According to Assoc. Prof. Dr. Nguyen Duy Thinh (Institute of Biotechnology and Food Technology, Hanoi University of Science and Technology), oysters and other bivalves (clams, oysters, mussels, etc.) live in the sediment, feeding on mud, algae, and plankton, making them susceptible to various bacteria and parasites, including flukes, especially oysters living in estuarine areas.
Oysters and other bivalves (clams, oysters, mussels, etc.) live in sediment, feeding on mud, algae, and plankton, making them susceptible to various bacteria and parasites…
“Eating raw oysters doesn’t just pose a risk of flesh-eating bacteria; we all face a high risk of fluke infections, food poisoning, and many other terrifying parasites,” Assoc. Prof. Dr. Nguyen Duy Thinh affirmed.
This expert further noted that the danger of eating raw oysters in salty water areas also lies in the possibility of heavy metal contamination, which can accumulate in the body over time, potentially leading to chronic and dangerous diseases.
Currently, environmental pollution is widespread, so consuming raw foods in general carries various health dangers. Oysters are no exception. However, it cannot be denied that raw oysters provide many nutritional benefits for health.
Raw Oysters and Vibriosis
Many people enjoy eating raw oysters, and restaurants serving raw oyster dishes are becoming increasingly popular. However, eating raw or undercooked oysters and other shellfish can put you at risk for Vibrio infections.
Vibrio bacteria naturally inhabit coastal waters where oysters live. Because oysters filter feed, Vibrio and other harmful bacteria and viruses can concentrate in their tissues. When you eat raw or undercooked oysters, you are at risk of contracting these microbes.
Most cases of Vibrio infections from oysters, such as those caused by Vibrio parahaemolyticus, present with diarrhea and vomiting. However, people infected with Vibrio vulnificus can become very ill. One in five people infected with Vibrio vulnificus will die. This is because infections from Vibrio vulnificus can lead to bloodstream infections, severe blistering skin lesions, and amputations.
Therefore, if you have recently eaten or touched raw oysters or other live shellfish, or have been exposed to saltwater or brackish water and are displaying symptoms of illness, you need to inform your doctor for proper diagnosis and treatment.
To eliminate the risk of flesh-eating bacteria, avoid going to the sea with an open wound.
According to experts, if you really want to benefit from the nutrients in raw oysters, you should buy fresh oysters, discard dead or spoiled ones, soak them in saltwater or brine to expel impurities, and then consume them. Additionally, you can safely eat oysters by cleaning and preparing them properly, salting them before consumption.
Furthermore, to eliminate the risk of flesh-eating bacteria, you need to avoid going to the sea with an open wound. After returning from the beach, rinse thoroughly with clean freshwater, and if you notice any swelling or redness on your skin, clean the area thoroughly with fresh water. If this condition does not improve after 4-5 hours, seek medical attention immediately to avoid complications as soon as possible.
