(Fighting new crown pneumonia) "two mysteries" surrounding the source of new crown pneumonia

China News Service, Beijing, February 29th: "Two mysteries" surrounding the source of the new crown pneumonia epidemic

Author Guo Chaokai Zhang Su

Zhong Nanshan, an academician of the Chinese Academy of Engineering, recently said that "new crown pneumonia may not originate in China." Today, there are still two mysteries surrounding the source of the new crown pneumonia epidemic that need to be resolved urgently: First, is the origin of the epidemic the Wuhan South China Seafood Market? Further questioned whether the epidemic originated in China?

Is the South China Seafood Market the birthplace of the epidemic?

Virus traceability is an "must answer" for epidemic prevention and control. At this stage, bats are the natural host of neocrown virus, which has been widely recognized in the academic community. Some scientific studies have pointed out that animals such as pangolins, snakes, and turtles are potential intermediate hosts of neocrown virus. The spread of human society is still unknown.

The picture shows the surrounding area of ​​Wuhan South China Seafood Market. Photo by Yang Chengchen of China News Agency

Since the outbreak, the South China Seafood Market has become a "public criticism". A virus tracing study released by the Chinese Center for Disease Control and Prevention on January 26 showed that 33 samples of New Crown Virus nucleic acid were detected from 585 environmental samples in the South China Seafood Market, suggesting that the virus originated from wild animals on the market.

However, with the deepening of research, more research shows that the epidemic situation may appear before the South China seafood market. A paper published by Huang Chaolin, deputy director of Wuhan Jinyintan Hospital, and others in the medical journal "The Lancet" showed that only 27 of the 41 cases had a history of exposure to the seafood market. In particular, it should be noted that the first onset of disease on December 1, 2019 The patient had no history of seafood market exposure.

The research results released by the Xishuangbanna Tropical Botanical Garden of the Chinese Academy of Sciences on February 20 also have similar conclusions: The South China seafood market is not the origin of the epidemic, but "helps the flames" in the epidemic. This study analyzed 58 haplotypes from 93 virus samples in the existing database to understand the evolutionary relationship of different virus samples. The results showed that the new crown virus had two significant population expansions before February 12: one was on December 8, 2019, meaning that the virus may have spread from person to person in early December or even late November, and the transmission speed was in the South China seafood market. Accelerate; another population expansion occurs on January 6.

Many people speculate that there may be multiple origins of the new crown virus. Yang Zhanqiu, deputy director of the Institute of Virology of Wuhan University Medical College, said that the new crown virus may have multiple origins in the same period, and may originate from different animals, different people or different regions, which will bring more opportunities for finding the source of the virus and preventing and controlling the epidemic. More challenges.

Regarding the above research, Zeng Guang, chief scientist of epidemiology at the Chinese Center for Disease Control and Prevention, told reporters from the China News Agency: "This is a useful academic discussion, but whether the conclusions of the study are valid still requires multi-faceted evidence."

Did the new crown pneumonia outbreak originate in China?

The new crown pneumonia epidemic is spreading globally. Recently, South Korea, Japan, Italy, the United States and other countries have seen many cases of local transmission. Some patients have no history of visiting China, which has made the outside world think more about the origin of the epidemic.

Researchers are demonstrating the experimental process of developing a new coronavirus mRNA vaccine. Photo by Tang Yanjun

Previously, two studies by the Guan Yi team at the University of Hong Kong and South China Agricultural University isolated coronaviruses highly related to neocoronaviruses from Malay pangolins. These Malay pangolins were seized from anti-smuggling operations, and the above-mentioned research has also heated up the debate about whether the new crown virus may enter China from abroad.

Zhong Nanshan pointed out that the epidemic occurred first in China, but not necessarily in China. Because from the perspective of scientific research, "first discovery" and "origin" cannot be equated, "but we cannot judge the epidemic from abroad".

The flu that began to sweep the United States in the fall of 2019 has infected 26 million people and killed as many as 14,000. In view of the similar symptoms of influenza and new-coronary pneumonia, Japanese media had suggested that "some of the 14,000 people who died from flu in the United States may have died of new-coronary pneumonia", but this claim was subsequently denied by the US Centers for Disease Control and Prevention.

Whether the flu epidemic in the United States is related to the new crown virus has also attracted Zeng Guang's attention. He said that in the past, the United States had strong laboratories and advanced concepts in epidemic prevention and control, and played a leading role in epidemic surveillance. "At present, there are no other pathogens other than influenza viruses in the flu epidemic in the United States." Sufficient experimental ability can be identified, and a fair explanation should be given in the follow-up.

Regarding the discussion on the country of origin of the epidemic, Zeng Guang said, "The academician Zhong Nanshan put forward the scientific hypothesis. This is a very valuable and open discussion. The key lies in the ability to start actual transnational scientific investigations and research demonstrations." He suggested that the World Health Organization should coordinate related work to study whether unknown coronaviruses of the same type around the world are of the same type and what are the differences in genetic sequences to track the true origin of the epidemic.

Interviewed experts emphasized that under the epidemic, "global is the same as this," the traceability of the new crown virus is not entangled in the national and regional disputes, let alone mutual "throw the pot." When the World Health Organization has raised the global risk level of the epidemic to "very high", international cooperation in virus traceability will help clarify the origin, intermediate hosts, and transmission modes of the virus, and cut off the virus transmission path as much as possible. Is the right meaning in the question. (Finish)