Stanford University researchers have moderated their controversial estimation of how many people were infected by COVID 19 in Santa Clara County by early April, but maintain that the disease is much more severe than anyone knew.
In a revised study published last month, 2.8% of Santa Clara residents have been previously infected but did not know the disease. They estimate that the virus was infected.
This implies that up to 54,000 infections were present in the county – many more than 1,000 confirmed cases at the time.
This suggests that the vast majority of the population have no antibodies and may be susceptible to the virus, the research paper, published in the medRxiv online report concludes.
If real, it suggests that the vast majority of people who developed COVID-19 in the pandemic’s early days have recovered without ever realizing they were infected with it. It also means the mortality rate is lower than expected, with too many undetected infections.
Stanford researchers tested 3,330 people on April 3rd and April 4th at three locations across Santa Clara County — two county parks in Los Gatos and San Jose and a church in Mountain View — to get a snapshot of how many people in the county had already been infected but weren’t seriously sick and didn’t realize they ever had the virus. They were searching for antibodies to the pathogen, a past infection marker that means going back to work, and school may be safe for them.
The study’s biggest problem has to do with test specificity. It used a kit bought from Premier Biotech based in Minneapolis with known discrepancies in the performance data. Though at the time of the study it was the best test, it had a high “false positive” rate that could distort results, critics say — especially with such a limited sample size.