PandemicsHow Coronavirus Took Hold in North America and Europe
Early interventions were effective at stamping out coronavirus infections, but subsequent, poorly monitored travel allowed the virus to ignite major outbreaks in Europe and North America, according to a new study.
A new study combines evolutionary genomics from coronavirus samples with computer-simulated epidemics and detailed travel records to reconstruct the spread of coronavirus across the world in unprecedented detail.
Published in the journal Science, the results suggest an extended period of missed opportunity when intensive testing and contact tracing might have prevented SARS-CoV-2 from becoming established in North America and Europe.
The paper also challenges suggestions that linked the earliest known cases of COVID-19 on each continent in January to outbreaks detected weeks later, and provides valuable insights that could inform public health response and help with anticipating and preventing future outbreaks of COVID-19 and other zoonotic diseases.
“Our aspiration was to develop and apply powerful new technology to conduct a definitive analysis of how the pandemic unfolded in space and time, across the globe,” said University of Arizona researcher Michael Worobey, who led an interdisciplinary team of scientists from 13 research institutions in the U.S., Belgium, Canada and the U.K.“Before, there were lots of possibilities floating around in a mishmash of science, social media and an unprecedented number of preprint publications still awaiting peer review.”
The team based their analysis on results from viral genome sequencing efforts, which began immediately after the virus was identified and quickly grew into a worldwide effort, unprecedented in scale and pace, that has yielded tens of thousands of genome sequences, publicly available in databases.
Contrary to widespread narratives, the first documented arrivals of infected individuals traveling from China to the U.S. and Europe did not snowball into continental outbreaks, the researchers found.
Instead, swift and decisive measures aimed at tracing and containing those initial incursions of the virus were successful and should serve as model responses directing future actions and policies by governments and public health agencies, the study’s authors conclude.
How the Virus Arrived in the U.S. and Europe
A Chinese national flying into Seattle from Wuhan, China on Jan. 15 became the first patient in the U.S. shown to be infected with the novel coronavirus and the first to have a SARS-CoV-2 genome sequenced. This patient was designated “WA1.” It was not until six weeks later that several additional cases were detected in Washington state.
