Will COVID-19 spread through food? Are frozen chicken wings positive and cherries positive? ... Recently, many foods have been tested positive for nucleic acids on the outer packaging or inner surface, which has aroused public doubts: Can all kinds of foods, especially imported foods, be safe to eat? Can COVID-19 be transmitted to people through food?
Authoritative experts recently said in an interview with reporters that the positive detection of nucleic acid in food does not mean that there is a live virus. Even if there is a live virus, it does not mean that it will definitely infect people. The main routes of transmission in COVID-19 are still droplets and contact infection. As long as ordinary consumers adhere to good hygiene habits, the probability of infection through diet is very small.
"It is not surprising that the nucleic acid on the surface of the commodity is positive. The most important thing to note is whether such a' positive' is contagious. " Kai Zhong, director of Kexin Food and Nutrition Information Exchange Center, told reporters that at present, the detection method of nucleic acid in COVID-19 is aimed at its RNA, which can detect whether the virus is dead or alive, even if it is "dead". A positive nucleic acid test may be a live virus, a dead virus or a virus fragment, which does not necessarily mean that it is contagious.
If there is a live virus in food, will it infect people? Wu Zunyou, chief epidemiologist of China CDC, explained that there is a very objective index called CT value in laboratory testing. The larger the CT value (for example, higher than 30 or 35), the smaller the pollution and the lower the probability of containing live virus; However, if the CT value is less than 30, it means that the pollution is relatively large and the possibility of live virus will be higher. In all the imported cold chain foods and commodities in China, tests show that most CT values are relatively high, that is, the pollution is relatively light. Generally speaking, the infection caused by pollution must be relatively large, and it also needs long-term repeated contact to cause infection. Therefore, there are relatively many cases of infection among cold chain practitioners, especially logistics stevedores.
"For consumers, even if they accidentally buy contaminated food, the risk of infection is usually very low. Even if they eat contaminated cold chain food, they usually will not cause infection." Wu Zunyou said, because on the one hand, food has inactivated the virus during cooking and processing; On the other hand, COVID-19 is not transmitted through the digestive tract, and human gastric acid is enough to inactivate it. So far, no diseases causing respiratory infection through digestive tract have been found, at least not in COVID-19.
Recently, the relevant personnel found that the number of imported goods tested positive for nucleic acid has increased compared with before, which is actually a normal phenomenon. Kai Zhong analyzed that this may be related to factors such as the epidemic situation in foreign countries has not been completely controlled, and the low temperature in winter in China will prolong the survival time of the virus. "At present, the epidemic situation in all parts of China is mainly human-to-human transmission caused by cold chain employee infection and human-to-human transmission caused by overseas importers. The super-transmission events that lead to the expansion of the epidemic are all human-to-human. Although all kinds of imported goods have been found to be positive, ordinary consumers have not been found to be infected by contaminated goods. Obviously, it is better to prevent people than things. Early detection, early reporting, early isolation and early treatment are the keys to epidemic prevention and control. "
So what should we pay attention to when purchasing and handling food? Kai Zhong reminded consumers that if they buy cold-chain food, they should wear masks when they go shopping, pay attention to hygiene during shopping and subsequent treatment, and don't touch their eyes, nose and mouth. For fruits, as long as we pay attention to hand hygiene and wash them with running water before eating, there should be no risk of infection.
Source: Economic Daily