Where does the new coronavirus originate? This is the answer that many scientists are eager to find. A Chinese joint team’s paper published on January 24 in the top medical journal “The Lancet” studied the clinical characteristics of the first 41 cases and provided important clues to trace the source of the epidemic.
On January 26, the website of the US “Science” magazine published a news report stating that the South China seafood market may not be the source of the virus, or it may be introduced from other places. Some international infectious disease experts made this guess based on the details of the data in the The Lancet paper. Subsequently, Cao Bin, one of the corresponding authors of the Lancet paper and director of the Department of Respiratory and Critical Care at the China-Japan Friendship Hospital, emailed The response said: “It now appears that the seafood market is obviously not the only source of the virus.”
Daniel Lucey, an infectious disease expert at Georgetown University in the United States, noted that according to the description of the The Lancet paper, the first confirmed patient developed the disease on December 1, 2019, and has not reported exposure to the South China seafood market. In addition, no epidemiological link was found between this patient and subsequent cases. Of a total of 41 cases, 13 were not linked to the seafood market.
“This number is large, 13 cases, there is no connection,” Luxi told Science. Based on the above data, he believes that given the incubation period of the new viral pneumonia, the first human infection should occur in November or even earlier. In this case, before the disease concentrated in the seafood market, the virus may spread silently among the population in Wuhan and even in other places. “The virus first entered that market and then came out of the market.”
Roussi mentioned that the coronavirus that caused the Middle East Respiratory Syndrome (MERS) was first detected in a Saudi patient in June 2012. However, follow-up studies have shown that the virus dates back to unknown pneumonia that broke out in a Jordan hospital in April of the same year.
He suggested that retrospective analysis of relevant human and livestock blood samples, including other animal trading markets, may provide more information.
Kristian Anderson, an evolutionary biologist at the Scripps Research Institute in the United States, also sequenced the new coronavirus in an attempt to trace the source. He also noted the details of the first patient’s onset on December 1. In his opinion, there are three ways that the virus can appear in the seafood market. The first two are an infected animal or a group of infected animals. The third is that someone is infected outside the seafood market and then brings the virus into the seafood market. .
“It seems that the seafood market is obviously not the only source of the virus.” Cao Bin responded to Science by email. “But honestly, we still don’t know where the virus came from.”
As most of the first patients with new-type coronavirus pneumonia were related to the South China Seafood Market, the market was closed on January 1. From the 585 environmental samples from the South China Seafood Market, the China CDC detected 33 samples containing the new coronavirus nucleic acid. These positive samples were distributed in 22 stalls and 1 garbage truck on the market.
The South China Seafood Market is called the Seafood Market, but there are many wildlife dealers in the area near the 7th Street and 8th Street in the western district, and the positive samples in this area are also concentrated, accounting for 42.4% of all positive samples (14/33 ), Which shows that the outbreak is likely related to the wildlife trade.