The UCHealth Hospital system said more than 12,400 Coloradans have opted to get tested to find out if they were ever infected with the novel coronavirus.
About a week ago UCHealth began offering antibody tests to anyone in Colorado.
The antibody test, done by drawing blood, can determine whether someone has been exposed to or contracted the virus in the past.
Of those tested, UCHealth said less than 500 came back positive. That's less than 4 percent of those tested.
Among UCHealth staff and providers only 2.3 percent tested positive for antibodies.
"While one might expect health care workers in hospitals would have higher rates of exposure, the results that we've seen so far indicate our employees and providers have lower rates of infection," said Rob Welch, UCHealth's lead laboratory director. "This suggests that our education efforts, personal protective equipment, social distancing and the strong infection prevention measures put in place by UCHealth at its hospitals and other health care facilities do indeed work, and our employees are following safety guidelines when they are not at work as well."
UCHealth said its antibody tests have been evaluated by the FDA, and "far exceed" the agency's accuracy and specificity requirements, and that its tests are "among the most accurate" offered in the nation.
UCHealth also reminds everyone that a positive test does not mean a person should feel safe from COVID-19. That's because doctors and scientists do not yet know if having antibodies gives a person immunity from contracting the virus again.
More information on COVID-19 testing is available on the UCHealth website or the UCHealth mobile app.