Coronavirus arose in China between early October and mid-November in 2019, with the most likely date of origin being November 17, according to UK scientists.
Research led by the University of Kent suggests that the first Covid-19 case outside China occurred in Japan on January 3, 2020, while the first case in Europe occurred in Spain on January 12, 2020, and the first case in North America occurred in the US on January 16, 2020.
According to official data, Japan confirmed its first case on January 16, Spain on January 31 and the US on January 21.
The findings, published in the journal PLOS Pathogens, are based on a new modelling method, which was originally developed to date extinctions rather than the origins of a new pandemic.
Dr David Roberts, from Kent’s school of anthropology and conservation, who helped develop the technique, said: “This novel application within the field of epidemiology offers a new opportunity to understand the emergence and spread of diseases, as it only requires a small amount of data.”
The first probable case of Sars-CoV-2 (the virus that causes Covid-19), investigated by a team from the World Health Organisation (WHO) was on December 8 2019, although the origins of the ongoing pandemic remain unclear.
Revealing their findings in February this year, the WHO scientists said that this case did not have any links to the animal market in Wuhan, China, which was initially thought to be where the coronavirus “spillover” from animals to humans occurred.
China, meanwhile, has faced claims that the Wuhan Institute of Virology could be the suspected source of the Covid-19 virus through a laboratory-related incident.
But at present, most scientists favour the theory that the virus spilled over from an animal to a human in nature.
Commenting on the findings, Professor Ben Neuman, chair of biological sciences at Texas A&M University-Texarkana in the US, and visiting associate professor at the University of Reading, said that the conclusions from the research “are roughly in line with those of other studies”.
He said: “It looks as though any way you slice it, the first case was around November, somewhere in China.
“This study does not pinpoint the location of the first case within China, or identify any previous hosts of Sars-CoV-2-like progenitor viruses.
“To answer those questions, we certainly need more genetic data on similar viruses, wherever they may be found.”