The virus that causes COVID-19 could have started spreading in China as early as October 2019, two months before the first case was identified in the central city of Wuhan, a new study showed. Reuters writes this.
“Researchers from Britain's University of Kent used methods from conservation science to estimate that SARS-CoV-2 first appeared from early October to mid-November 2019, according to a paper published in the PLOS Pathogens journal. The most likely date for the virus's emergence was Nov. 17, 2019, and it had probably already spread globally by January 2020, they estimated,” the publication writes.
China's first official COVID-19 case was in December 2019 and was linked to Wuhan's Huanan seafood market. However, some early cases had no known connection with Huanan, implying that SARS-CoV-2 was already circulating before it reached the market. Researchers now believe that before the first outbreak, cases of infection could occur pointwise across the country. The cause of the virus has not yet been determined, but there are two theories: the transmission of the infection to humans with animal food and the leak of the laboratory that worked to create the virus.
In a new study, scientists restored data on the sequencing of the first samples of the virus detected in Wuhan, and it became clear that they were already a modified version of the coronavirus. It turns out that the virus did circulate before the first confirmed cases of infection.
The U.S. National Institutes of Health confirmed to Reuters that the samples used in the study were submitted to the Sequence Read Archive (SRA) in March 2020 and later deleted at the request of Chinese investigators, who said they would be updated and submitted to another archive. Critics said the deletion was further evidence that China was trying to cover up the origins of COVID-19.
Another study by Australian scientists, published on Thursday in the Scientific Reports journal, used genomic data to show SARS-CoV-2 binds to human receptors far more easily than other species, suggesting it was already adapted to humans when it first emerged.
When asked about the accuracy of the laboratory origin of the coronavirus, the researchers said that "such conclusions remain speculative" and "it may be some time till we see reports like this."
On March 11, 2020, the World Health Organization announced the beginning of the coronavirus pandemic. Since then, about 180 million people have been infected and about 3.9 million have died in the world. 2.2 million people have been infected in Ukraine. 52,234 cases have been fatal.