BY SARA TABIN
Daily Post Staff Writer
Stanford researchers think about 2.5% to 4.2% of Santa Clara County residents, or 48,000 to 81,000 of the county’s 1.9 million people, have been infected with COVID-19.
Santa Clara County has reported 1,870 cases and 73 deaths. The county’s case numbers are understood to be an undercount of the real number of infections because of a national testing shortage.
The new statistics are part of a study led by Dr. Eran Bendavid, an associate professor of Primary Care and Population Health at Stanford Medicine.
Bendavid and his team collected blood samples from 3,330 county residents who volunteered to participate in the study. By analyzing the prevalence of COVID-19 antibodies in the blood samples the researchers came to the conclusion that the real number of infections is 50 to 85 times higher than what the county has reported.
Similar to San Mateo County estimate
Those numbers are similar to an estimation San Mateo County’s Health Officer Dr. Scott Morrow made earlier this week. Morrow said 2-3% of San Mateo County’s 768,808 residents have probably had the virus and recovered. He said the region’s stay-at-home order probably prevented the disease from spreading faster.
People who have already had COVID-19 might have protection against getting the disease again because of the antibodies they develop. No one knows yet whether that immunity is permanent.
The Stanford researchers used Facebook ads to recruit test subjects from different areas and backgrounds. They attempted to adjust results for race, Zip code and sex to make the sample better reflect the broader population.
More sick people signed up?
Natalie Dean, an assistant biostatistics professor at the University of Florida, said on Twitter that the study might have had a selection bias where people who thought they might be sick would be more likely to sign up.
The study results are part of a pre-print research paper, meaning the paper has been put online but has not been peer-reviewed by other medical experts.
Bendavid and Dr. Jay Bhattacharya, another Stanford professor and one of the paper’s co-authors, published an op-ed in the Wall Street Journal last month saying estimates which put the death toll for COVID-19 at 2-4% might be too high because infections have been undercounted.
They said more information about its spread in the population is needed to know how many people who contract the virus will die. They said the death toll of the country might be closer to 20,000 than 2 million.
So far 33,049 Americans have died from COVID-19, but the disease is still spreading.
Certain populations, such as older people and those with other medical conditions, are more at risk for dying from COVID-19.
In the absence of widespread testing, hospitalization numbers can also shed some light on how serious the situation is getting. California has seen less hospitalizations and deaths compared to other places like New York City.
There are 187 people currently hospitalized for COVID-19 in Santa Clara County. There are 71 people hospitalized due to COVID-19 in San Mateo County.