Study: Placer County COVID-19 infections likely 3 times higher than number of confirmed cases - KCRA Sacramento

Led by Stanford University School of Medicine, study investigators tested blood samples from 2,035 residents between October and March for COVID-19 antibodies using rigorous methods, according to a news release.

The reason for the discrepancy is that some of those infected may not have developed symptoms or never got tested or never sought to be tested, according to the news release.

"The good news is that Placer County has done a great job protecting its most vulnerable people with masking and social distancing," said the study's principal investigator, Dr.