Winter Food Poisoning: Why You Should Be Cautious About Eating Oysters

Food poisoning often occurs more frequently in the summer when food is prone to spoilage. However, norovirus is one of the foodborne pathogens that requires more attention in winter than summer. Norovirus is a very small, highly contagious virus causing gastroenteritis, and it can infect people of all ages. Since it can survive even at temperatures below -20°C, special precautions are necessary.

‘Oysters’ in season, Norovirus, One of the food ingredients that trigger it

When we think of winter seafood, oysters often come to mind. Often referred to as the “milk of the sea,” oysters are not only delicious but also nutritionally rich. The best time to enjoy them is during January and February when the water temperature drops further. However, as one of the food ingredients that can trigger Norovirus, it is better to eat cooked oysters rather than raw. If you’re going to eat raw oysters, it is recommended to sprinkle salt on oysters intended for sashimi, then rinse them thoroughly with clean water before consumption.

What’s the difference from gastroenteritis?

Norovirus and common gastroenteritis both cause similar symptoms of gastrointestinal diseases, but their causes are a bit different. Norovirus refers to a specific type of virus that causes acute gastroenteritis, while gastroenteritis is a general term encompassing inflammation of the intestines caused by various pathogens such as rotavirus or adenovirus. Although they may seem similar, the different causative agents lead to slightly different symptoms and treatment approaches.

What causes a Norovirus infection?

Norovirus can be transmitted through the consumption of contaminated water or food, contact with an infected person, and exposure to the feces or vomit of an infected person. It occurs more frequently in winter and can withstand various temperature changes. The virus’s ability to survive in cold weather and the increased time spent in enclosed spaces due to the cold weather can enhance its transmission between people.

Symptoms when infected

Norovirus typically has an incubation period of 24 to 48 hours, after which the following symptoms occur: sudden dizziness or nausea are usually initial symptoms. You may also experience abdominal cramps or pain, and watery diarrhea is one of the prominent features of Norovirus infection. If diarrhea is frequent and not appropriately treated, dehydration can occur.

How do I know if I am infected with Norovirus

If you suddenly start vomiting or have diarrhea after eating seafood, or if the people who ate with you also show similar symptoms, you should check. If you have symptoms of fever, chills, or muscle pain in addition to digestive disorders, there is a high probability that you have been infected with Norovirus.

There is no specific treatment

The truth is, Norovirus naturally heals over time, and there is no specific treatment. Therefore, the use of antibiotics is generally discouraged, and symptomatic treatment is needed. Since it’s easy to become dehydrated due to diarrhea and vomiting, it’s crucial to replenish fluids. For this, electrolyte drinks, sports drinks, barley tea, etc., are recommended. You should avoid carbonated drinks or fruit drinks with high sugar content as they can exacerbate digestive symptoms.

Highly contagious

Norovirus is highly contagious, so if you’re infected, it’s best not to touch or prepare food for others to eat. Even if symptoms such as vomiting or diarrhea have disappeared, the virus can still be transmitted for up to two days afterward, so you should be careful not to mix your breath with others. Also, you should always use separate towels and bedding.

To enjoy oysters safely and deliciously

Shellfish, including clams and oysters, should be thoroughly cooked before consumption. It is also recommended to boil or heat groundwater before drinking. Norovirus is highly resistant, even surviving heating at 60°C for 30 minutes, so thorough cooking is crucial. If you heat food materials, they should be heated to 80°C for 5 minutes or 100°C for 1 minute to ensure the inactivation of the virus.

Washing hands thoroughly

Norovirus is highly contagious, so prevention can be achieved simply by washing your hands well. After using the bathroom or changing diapers, and before eating or preparing food, you must always wash your hands. When washing your hands, wash them thoroughly with soap for at least 30 seconds under running water. Also, be careful not to touch cooked food with your bare hands and drink bottled water that has been stored hygienically if you cannot boil water.

Preventing contact

When using the toilet, it is important to close the toilet lid, flush, and thoroughly disinfect the surrounding area. If vomiting occurs, cover the vomit with a paper towel soaked in disinfectant for about 5 minutes, then dispose of it in a sealed plastic bag. Additionally, it is advisable to diligently disinfect surfaces that come in contact with hands, such as doorknobs and faucets.

By. Shin Young Jeon