A new study from the University of Texas at Austin reveals the novel coronavirus was raging through Seattle months before the first case was reported.
Researchers estimate Seattle already had at least 9,000 cases by March 9, when the city implemented lockdown measures.
Of these, thousands likely involved children.
As COVID-19 was initially unknown, cases were misdiagnosed as influenza.
At the time, Gizmodo reports there were fewer than 200 cases reported in the state as a whole.
The University of Texas at Austin researchers also estimate that people may have been spreading the virus in Seattle as early as Christmas.
