Study: COVID-19 nearly 7 times more prevalent in Orange County than previously thought

The coronavirus is nearly seven times more prevalent in Orange County than previously thought, according to results from a new antibody study.

Researchers with the University of California, Irvine, in collaboration with the county's Health Care Agency, tested a sample of Orange County residents and found that 11.5% of them have antibodies for the virus.

Previous estimates had pegged that number at 2%, officials said.

The study was initiated because researchers had a "hunch" that the presence of the virus in the county had been "underestimated," officials said.

"There was this lurking suspicion that there's a large fraction of people who have had it that did not know," said co-principal investigator Tim Bruckner, associate professor of public health. "Either they had symptoms and did not seek care, or they did not have symptoms and had no reason to go."

The study also found that Latino and low-income residents had the highest rates of COVID-19 antibodies, 17% and 15%, respectively.

"This rigorously designed surveillance study offers important information about how many residents of Orange County have already been exposed to COVID-19," said Bernadette Boden-Albala, director of UCI's Program in Public Health, in a press release. "Additionally, the study helps us to understand the impact of disparities."

Researchers say the study results will help identify key demographics that are at higher risk of contracting the virus, and subsequently developing serious illness as a result.