These days, the COVID-19 epidemic in Beijing has touched everyone’s heart. On the one hand, Beijing’s epidemic prevention work responded quickly and acted in an orderly manner, which calmed the anxiety of Beijing residents about Covid-19. On the other hand, to do a good job of self-protection and reduce the risk of infection, it is necessary to implement the actions of every resident.
Although it is not confirmed at present whether aquatic products such as salmon are infected by viruses themselves, contaminated by virus-carrying workers before import or artificially contaminated in the follow-up treatment after entering the market, it still brings a new test to our safety belt on the tip of our tongue.
Can and how to eat salmon and seafood? How can we reduce the risk that the ingredients themselves may be infected with viruses? Let’s listen to what two authoritative experts say.
No matter how the epidemic changes, we should be cautious, avoid excessive panic and believe in the official conclusion.
What is the relationship between salmon and Covid-19?
The possibility of salmon "carrying" virus in the body is very low.
Salmon carrying Covid-19 and bats carrying Covid-19 are two different things. If the "carrying" of salmon is confirmed, it is precisely contaminated or contaminated. The "carrying" of bats is a host that can coexist. At present, all the known hosts in Covid-19 are mammals, so the possibility of carrying Covid-19 in salmon is almost zero.
The news we have seen so far is that the chopping board for cutting salmon has detected the virus. It depends on whether this chopping board cuts anything other than salmon, but also excludes secondary pollutant salmon.
Assuming that the virus is indeed brought by salmon, the report we have seen so far is that the virus sequence is confirmed to be a European strain, so it is reasonable to infer that salmon from Europe is polluted in Europe. It is still difficult to confirm whether the salmon is polluted or the foam box or the crushed ice inside is polluted. But it can be speculated that there may be infected people among those who participate in the fishing, processing and transportation process.
There is a great possibility of transmission through mucosal contact.
At first, more than 50 people were diagnosed positive. You said it was spread by salmon. Personally, I don’t believe it. Because Covid-19 can’t replicate outside warm-blooded animals, there should be a lot of viruses to infect more than 50 people. Therefore, if the fact of transmission is confirmed in the future, it is most likely that salmon will be transmitted to people at first, and then to others.
How did it pass? Personally, I think it is very likely to spread through mucosal contact, such as touching contaminated chilled salmon, rubbing your eyes and picking your nose without washing your hands, or polluting the booth and surrounding environment through salmon, and then spreading through contact.
Not so far.
Evidence of COVID-19’s direct transmission through eating and drinking.
In fact, up to now, there is no evidence of direct transmission through eating and drinking in COVID-19, mainly through contact transmission. If it is cooked food, of course, there will be no problem. If it is eaten raw, the risk will be greater, because the chances of the virus contacting the mucosa are a little more.
Covid-19’s survival time on the surface of objects ranges from several hours to several days. The chilled salmon is transported by air and protected by low temperature, so it is theoretically possible to survive. Although this probability is not great, considering that once an epidemic situation is caused, the cost of prevention and control is extremely high, so such products may be controlled in the near future.
For individuals, it is unlikely that Covid-19 will be infected by raw salmon, but it is a completely unnecessary risk. To be on the safe side, I suggest that you don’t eat raw salmon and other imported fresh food recently, and wait until the official investigation results are clear before making a decision. When frying, it should be fine if it is half-baked, because it is superficial.
In addition, the main means of self-protection is to go out to buy and wear masks, wash your hands at home, wash your hands before and after making food, and try not to touch your eyes, nose and mouth with dirty hands. Be vigilant, but don’t be scared.
Text/Kai Zhong (Doctor of Food Safety)
Nine suggestions for home cooking to ensure food safety
The COVID-19 incident in Xinfadi has sounded the alarm for us, reminding us once again that food may carry a variety of pathogenic microorganisms, including infectious viruses, and we must handle it carefully to avoid possible pollution in the kitchen. Especially in the hot summer, microorganisms multiply faster, and human gastrointestinal function and disease resistance may decline, so we should be more alert to the risks brought by pathogenic microorganisms.
For this matter, my personal suggestion is this:
1. Don’t eat sashimi, stir-fried, medium-rare steak and other foods that haven’t been fully sterilized for the time being.
The Chinese nation has been paying attention to cooked food since ancient times, which is a real cultural wisdom. In the era of underdeveloped social economy, the chances of bacterial and virus outbreaks have been greatly reduced. In view of the virus detected in imported fish, we should pay attention to avoid eating any fish, shrimp, shellfish and other foods raw in the near future.
In fact, aquatic food is originally a high incidence category of pathogenic bacteria. Even if Covid-19 is not considered, Vibrio parahaemolyticus, Salmonella, Vibrio cholerae and Shigella are often reported in seafood, and the pollution risk is unavoidable!
China has imported a large amount of pork and beef from the United States according to the trade agreement, and a very high proportion of employees in American meat processing plants have been infected with Covid-19 before, so we should be on high alert for meat. When eating meat, you must stew it thoroughly, and the temperature in the middle of the meat must exceed the death temperature of various viruses. Don’t simply stir-fry it for a minute or two, or eat half-cooked and undercooked meat — — No virus can withstand cooking at 100℃ for an hour.
2. When buying food, give priority to the supermarket.
The cut and repackaged goods are safer, because it can reduce the direct contact between shoppers and raw fish and meat, thus reducing the contact with viruses and various pathogenic bacteria.
3. In the shopping basket, do raw and cooked isolation.
When the supermarket staff gives you the bag containing fish and seafood, you should prepare another bag in advance, so that the staff can put the bag containing fish directly into it. On the one hand, an extra layer can avoid the leakage of the soup inside, and more importantly, the hands of the staff have been exposed to raw fish and raw meat, and the plastic bag is at risk of being contaminated. Your hands and other goods only touch the bag outside, not the bag inside. In this way, other foods in the shopping basket will not be polluted.
4. After buying home, the food should be handled in time.
After you buy it home, you should take it out immediately and treat it separately. Don’t leave it at room temperature for a long time. First, take out the vegetables and fruits and store them separately, and then take out the raw fish and meat. If it is eaten as a meal, put it in a special basin; If you want to continue cold storage or freezing, you can take the bag outside and put it in a fresh-keeping drawer or a frozen drawer dedicated to storing raw fish.
Please note that whether frozen or refrigerated, raw and cooked must be separated.
5. Containers, chopping boards, knives, pools and packaging that come into contact with raw fish should be properly handled to avoid pollution.
If there is only one pool, it is recommended to wash the fruits and vegetables first, and then the fish. It is best to use the chopping board knives and containers for cleaning and dividing raw fish. After cutting, wash the chopping board and pool in time, preferably by disinfection. Dishes and chopsticks that have been treated with raw fish should also be cleaned and disinfected in time. Put the bags filled with raw fish directly into the "other garbage" bucket, and don’t put them on the table or cupboard.
6. Pay attention to protect your hands and wash your hands in time to avoid pollution.
There is a certain risk of pollution in the process of handling raw food. If there is the possibility of puncture, it is best to wear thick gloves to operate. Many aquatic products carry pathogenic bacteria, and once they are stabbed, they are prone to infection, and there are even cases of death by marine Vibrio and other bacteria.
Direct operation is also easy to transfer bacteria to hands, so you can wear soft gloves to operate. If you operate directly by hand, you need to wash your hands thoroughly and disinfect them after handling. Also be careful not to touch other foods and containers before washing your hands.
7. When food is put into the freezer, it should be packaged strictly to avoid mutual pollution.
Use waterproof packaging, at least two layers of packaging. It is necessary to prevent microorganisms in raw food from polluting other foods, and also to prevent oxygen from entering the food smoothly, causing food oxidation deterioration.
Although frozen food can be stored at -18℃ for more than half a year, its flavor and taste will be worse, the nutrient content will be reduced, and the fat and protein will be oxidized to varying degrees. Eating early is good for food, nutrition and environmental protection. It’s best to write the date of putting it in the package to avoid wasting it for too long.
8. temporarily not eating imported fish and seafood will not hinder your health.
In fact, adding some bean products, beans, nuts and oilseeds, eating eggs, milk, chickens, ducks and geese normally, and enough fresh water aquaculture products can make our nutritional balance more reasonable.
If you are not sure, you will not eat imported salmon, tuna and the like for the time being, which does not mean that there is no source of DHA. In fact, offshore fish such as saury, hairtail, yellow croaker, flat fish and so on are also sources of DHA.
The determination shows that the DHA content of domestic freshwater fish carnivorous fish such as perch is not inferior to that of imported salmon, because the feed of these carnivorous fish contains sea fish meal, which contains DHA, and fish can accumulate DHA in the body from the feed.
9. It is safer to cook fish food in time, and then pack it and freeze it.
Raw fish food is better than frozen for a long time and then cooked again and again. It is better to treat it in time, cook more at a time, cook it and then divide it into several portions, and then refrigerate or freeze it. This can not only kill pathogenic microorganisms in time, but also avoid polluting the refrigerator and make it more convenient to eat. Take one serving at a time, heat it in a pot for a few minutes, or heat it in a microwave oven for two minutes until the central temperature reaches 70℃.
In fact, whether there is Covid-19 epidemic or not, the above suggestions on food safety are pertinent and applicable at any time.
In the past few years, tens of thousands of people in Germany were infected with norovirus and caused diarrhea, and there have been many cases of hepatitis A virus outbreaks in China. These are viral diseases that are transmitted through food.
Finally, by the way, don’t hoard all kinds of food, especially aquatic products. They are potential pollution sources, so why put them in your refrigerator in large quantities? It’s not worthwhile to spend a lot of money on fresh ingredients, spend a lot of electricity on storage, bear the risk of pollution, and then eat stale things.
Text/Fan Zhihong (Director of China Nutrition Society)
