University of Cambridge researchers have traced SARS-CoV-2 origins, indicating emergence as early as September 2019, likely outside Wuhan. Evidence supports a first human wave well before December.
A University of Cambridge study, reported by South China Morning Post on April 17, 2020, posits that SARS-CoV-2 first appeared in September 2019, not in Wuhan's market as officially stated for December 2019. Geneticist Peter Forster's team used phylogenetic networks—a mathematical tool mapping viral spread via gene mutations—to date the initial human wave between September 13 and December 7, 2019. The virus may have existed in mutated form months or years earlier.
Patient zero's location remains undetermined, but evidence points to areas south of Wuhan, not the city itself. SARS-CoV-2 shares 96% genetic similarity with a 2013 bat coronavirus from Yunnan province. Evolving at roughly one mutation per month, it likely circulated undetected in bats, other animals, or humans before becoming highly transmissible in humans.
Building on their March 30, 2020, PNAS paper analyzing 160 early strains, the team now incorporates 1,001 complete genome sequences for greater accuracy.
This study awaits peer review and verification. Phylogenetic methods have limitations, so further research is needed to confirm or refute these findings.
