How big is the risk of COVID-19 spreading from animals to humans? How to prevent it? Experts explain →

From January 9, when Tianjin announced the first confirmed local case of Omicron, within 10 days, Omicron had spread rapidly to 9 cities in 6 provinces. On the 18th, Beijing and Shenzhen reported the infection channels of the confirmed cases, and reminded everyone again: In addition to human-to-human transmission of the virus, we also need to pay attention to another route - human-to-human transmission.

Cases of infection with Omicron have been reported in Beijing and Shenzhen

The possibility of "transmission from animals to humans" cannot be ruled out

On January 17, the Beijing Center for Disease Control and Prevention reported that a confirmed case of the new coronavirus in Beijing's Haidian District had received international mail. 22 environmental samples from the international mail were tested positive for nucleic acid.

The investigation found that the international mail was sent from Canada on January 7, arrived in Beijing via the United States and Hong Kong, China, and the confirmed case received the mail on January 11.

The case self-reported: During this period, she only touched the outer surface of the mail packaging and the first page of the document paper, and did not touch the inner surface of the packaging and other papers. The Beijing Disease Control Department collected 22 environmental samples from the international mail, including 2 samples from the outer surface of the packaging, 2 samples from the inner surface, and 8 samples from the paper inside the document, all of which were positive after nucleic acid testing.

Pang Xinghuo, deputy director of Beijing Center for Disease Control and Prevention: Based on the epidemiological history of the case, the test results of samples of suspicious items, and the genetic sequencing results of case specimens, we cannot rule out the possibility that the person was infected with the virus through overseas items.

On the same day, Shenzhen, Guangdong also reported the progress of the epidemiological investigation of the first case of infection with Omicron in this round of epidemic. It is understood that the confirmed case was engaged in the receipt and delivery of frozen reagents abroad, and on January 12, he came into contact with and split the express from North America.

According to the comparison between the National Center for Disease Control and Prevention and the Guangdong Provincial Center for Disease Control and Prevention, the Omicron variant infected by him is not in the same transmission chain as the reported cases of local Omicron in Tianjin, Shanghai, Zhuhai and Beijing, and is not the same source as the previous imported cases in Shenzhen. It is 100% homologous to the genome with more sequences uploaded in North America in the global database. The Shenzhen Municipal Health Commission stated that it does not rule out the possibility that this outbreak was caused by exposure to contaminated items of the new coronavirus imported from abroad.

Why is international mail still "toxic" after disinfection?

Zhang Liubo, chief expert in disinfection at the Chinese Center for Disease Control and Prevention, said that the current global pandemic of the COVID-19 pandemic is still ongoing, and there is a possibility that mail and goods entering the country may be contaminated by the COVID-19. Some viruses may gradually die during transportation, but under certain conditions, some viruses will not die, and the goods will be contagious.

Experts also said that the new coronavirus will not only contaminate the packaging of mail, but also the goods inside. The fact that the relevant personnel in the express delivery industry did not get sick first shows that the protection and disinfection of the mail surface are effective, but the risk of transmission of the goods inside the packaging should be taken seriously.

How to ensure the safety of receiving international mail?

Experts suggest that the public can reduce or suspend non-urgent international mail. However, if you really need to receive international mail urgently, you should strictly disinfect it and take protective measures when handling mail.

The item tested positive for the coronavirus nucleic acid

Will it definitely be transmitted to humans?

In this regard, Zhao Wei, a professor at the School of Public Health of Southern Medical University, said that the nucleic acid test result of an object is positive, which does not mean that there must be live viruses on the surface of the object. After a period of time, the virus will lose its vitality, but the nucleic acid of the virus will still exist, which will result in the nucleic acid test result on the surface of the object being positive. If the virus on a positive object is to be transmitted to a human, at least three conditions must be met:

There must be a source of infection, which means that the virus on the surface of an object must be a living virus, not a dead virus. There must be a suitable transmission route, which for the new coronavirus is through the respiratory tract. There must be a susceptible population, which means that the people who come into contact with it must not be immune.

Source: CCTV News