However, in a paper published by The Lancet magazine in June 5438+ 10, Huang et al., vice president of Wuhan Jinyintan Hospital, analyzed the first batch of 4 1 cases.
Only 27 of them have been to South China seafood market. The retrospective study showed that the first confirmed case occurred in February 19+ 1 2065438, and there was no contact history with seafood market in South China, and no confirmed case was found in the later period.
There is an epidemiological link between them, and their families have never had fever or respiratory symptoms. American journal of science
Christian anderson, a biologist at Scripps Institute in the United States, speculates that COVID-19 may enter the seafood market in southern China in three situations: an infected person, an animal or a group of animals may bring it to the market. Many experts and studies support this view. Columbia University, known as the "virus hunter"
Walter ian lipkin, a professor at Melman School of Public Health, said that the connection between COVID-19 and South China seafood market may not be so direct. Perhaps the market is "secondary transmission" and the virus has already spread earlier. Researchers from Xishuangbanna Tropical Botanical Garden of China Academy of Sciences recently published a paper in preprint form, saying that they analyzed the genome data of 93 COVID-19 samples from four continents 12 countries and found 58 haplotypes. Haplotypes of patients related to China South seafood market are all H 1 or its derivatives, while H3, H 13 and H38 are more "ancient" haplotypes. In order to restore the transmission chain in COVID-19, scientists still lack some "puzzles", among which the most crucial one is the first infected person, usually called "patient zero". "patient zero" is the intersection of many questions, which is very important for finding intermediate hosts and answering questions such as how the virus spreads from animals to humans. A famous example is "Spanish flu". It is estimated that this flu killed tens of millions of people around the world a hundred years ago. Although the epidemic was named after the first report in Spain, some retrospective studies later found that the first infected person may be a soldier from a military camp in Kansas, USA. Daniel Luci, an infectious disease expert at Georgetown University, said that considering the incubation period of the virus, the first case of COVID-19 infection may appear at 20 19 1 1 or earlier. From the global spread of novel coronavirus, although most cases in COVID-19 can be traced back to the source of infection, the United States and other countries have also reported many untraceable cases. In Italy, where the epidemic is getting more and more serious, the domestic "patient zero" has not been found so far.