The first cases of Covid-19 likely occurred in China between early October and mid-November 2019, according to new data modelling that suggests the virus spread around the world far more quickly than was previously realized.
The first case was likely to have been on November 17, researchers said, in an analysis published in the journal PLOS Pathogens.
Officially, the first cases of Covid-19 were recorded in early December 2019, in the central Chinese city of Wuhan, although experts have long thought the virus was spreading between people before that.
This is also the view held by the team of World Health Organization (WHO) scientists tasked with studying the origin of the Covid-19 outbreak at the start of the year.
The data researchers, led by David Roberts of the University of Kent in Britain, calculated the most likely period of time it would have taken the pathogen to jump from animals to humans, based on information about the first confirmed cases in China and abroad.
They relied on a mathematical model from the field of conservation that is used to make predictions about the extinction of species.
The model suggests that the virus is likely to have spread worldwide as early as January.
The scientists’ calculations indicate that the first infections outside China could have occurred around January 3 in Japan.
In Europe, the first case would have been in Spain, near to January 12, according to their calculations; while the first infection in the United States would have been around January 16.
