The Chinese Centre for Disease Control and Prevention (CCDC) previously said that Covid-19 originated from the Huanan Seafood Wholesale Market in Wuhan.
Thought Covid-19 originated from Wuhan seafood market
Earlier media reports stated that the market had been illegally selling wildlife, which was believed to be the source of Covid-19.
The market closed down on Jan. 1, 2020.
New study claims Covid-19 was imported elsewhere
However, a new study done by scientists from China suggested that the disease was actually imported from elsewhere.
The study, done by Doctor Yu Wenbin and his team from Xishuangbanna Tropical Botanical Garden, under the Chinese Academy of Sciences and the Chinese Institute for Brain Research, was published on Feb. 20, 2020.
Genomic data of 93 Covid-19 samples provided by 12 countries were used to investigate the evolution and human-to-human transmissions of the disease within the past two months.
It was discovered that while Covid-19 had spread rapidly within the seafood market, there had also been two major population expansions on Dec. 8, 2019 and Jan. 6, 2020, South China Morning Post (SCMP) explains.
This suggests that Covid-19 had originated from outside the market, but the crowded market inevitably caused the spread of the disease to the entire city of Wuhan in early December 2019.
The scientists added that finding out whether the market is the only origin of Covid-19 is important, as they can now subsequently find the virus' source and determine its intermediate host.
This will then help to control the pandemic and prevent future spread.
China's initial warning did not have enough attention
Based on the genome data, the study also found that human-to-human transmissions could have started as early as November 2019.
The scientists explained that the initial Level 2 emergency warning issued by CCDC on Jan. 6, 2020 was not sufficiently shared.
Thus, some patients who only had mild symptoms could have been overlooked.
"We suggest that SARS-CoV-2 (Covid-19) may have already circulated widely among humans in Wuhan before December 2019, probably beginning in mid to late November. Some infected patients may have been overlooked because they had mild symptoms.
We have demonstrated that a phylogenetic approach can be incorporated into epidemiological studies to search for the original source of SARS-CoV-2 and identify the direction of human-to-human transmissions.
If the warning had attracted more attention, the number of cases both nationally and globally in mid-to-late January would have been reduced."
You can read the full study here.
Top image via Getty Images.