STANFORD (CBS SF) — New findings from Stanford University researchers study suggests coronavirus infections are much more widespread than what health authorities have determined.

The researchers tested 3,300 residents from throughout Santa Clara County for COVID-19 antibodies in early April. They found that among the people they tested, 2.5 to 4.2 percent of people had been infected; that’s compared to the reported infection rate of about 0.6 percent at the time.

That’s 50 to 85 times more than the number of confirmed cases.

The study has yet to be peer-reviewed, but it does reflect the belief of many medical experts – that the number of coronavirus infections is far higher than what’s been reported due to a lack of testing.

“We found that there are many, many unidentified cases of people having Covid infection that were never identified with it with a virus test,” said Dr. Jay Bhattacharya, one of the paper’s authors told CNN. “It’s consistent with findings from around the world that this disease, this epidemic is further along than we thought.”

“I think it tells us again that transmission of the virus and the virus are more common than just the number of people coming up a positive test which is fundamentally what is being counted at the state and national level,” said Dr. Art Reingold, UC Berkeley Professor of Epidemiology

Experts caution people should not draw broader assumptions on a study limited to the San Francisco Bay Area with subjects recruited on Facebook which could skew the results.