The first cases identified of the Wuhan coronavirus may have occurred south of Wuhan in September, a team of scientists led by the University of Cambridge found. The South China Morning Post reported the findings on Thursday.
In a newly published study, which has not been peer-reviewed, researchers investigating the virus’s origin analyzed global viral samples and concluded that the virus must have first infected humans between September 13 and December 7.
“The virus may have mutated into its final ‘human-efficient’ form months ago, but stayed inside a bat or other animal, or even human, for several months without infecting other individuals,” University of Cambridge geneticist Peter Forster, one of the study’s researchers, said.
“Then, it started infecting and spreading among humans between September 13 and December 7, generating the network we present in [the journal] Proceedings of the National Academy of Sciences [PNAS].”
According to the SCMP, the team analyzed the strains using a phylogenetic network — “a mathematical algorithm that can map the global movement of organisms through the mutation of their genes.” As of Thursday, they were still trying to pinpoint the exact location of “patient zero” and said to be hoping for help from scientists in China. However, some early signs were prompting them to look into areas south of Wuhan, where they say coronavirus infections were first reported in December.
Wuhan, in central Hubei province, is widely agreed to be the origin of the Chinese coronavirus. The Chinese government has taken the position that the virus originated in a U.S. Army laboratory, a claim no scientists have substantiated with any evidence.
“What we reconstruct in the network is the first significant spread among humans,” Forster said.
The Wuhan coronavirus’s origin has become a hotly debated issue. Beijing has promoted a conspiracy theory that the coronavirus was manufactured and introduced to China by the American army.