CA Officials Warn Of Inaccurate Results From COVID Rapid Tests

CALIFORNIA — More than two years into the pandemic, taking a quick coronavirus test at home has become almost household. But officials are now warning that an initial test will not be enough to determine whether a person is infected.

Last week, the U.S. Food and Drug Administration said that multiple tests should be used over two to three days, "especially when the people using the tests don't have COVID-19 symptoms."

Officials also urged that at-home tests are less accurate than molecular or PCR tests.

COVID-19 antigen tests are expected to detect the virus at least 80 percent of the time, according to the FDA. But the probability of getting a false-negative result is also higher among those symptomatic and infected with the dominant omicron subvariant BA.5.

An infection from the omicron variant family is also more likely to begin in the throat, UC San Francisco infectious diseases expert Dr. Peter Chin-Hong told the Los Angeles Times.

According to a small study published Wednesday, more than 56 percent of people infected with the omicron variant are unaware of their infection.

The study, conducted by researchers from Cedars-Sinai Smidt Heart Institute and the University of California, Los Angeles, revealed that those who were unaware of their symptoms likely only felt mild symptoms.

Data from the study also showed that awareness of infection did improve after at-home rapid test kits became widely available this year.

Still, people are encouraged to use tests often if they suspected they have been infected. Those who have symptoms who receive a negative test result are encouraged to test again 48 hours later. If the second test is negative, the FDA suggested a third rapid test or a PCR test if symptoms are still present.

"Use those rapid tests, they’re generally fairly reliable," Los Angeles County Public Health Director Barbara Ferrer said at a news briefing. "If you still have symptoms, and you’re testing negative, go ahead and get a PCR test.”

Ferrer suggested that those who say they have been repeat testing are likely doing it every few hours. Alternatively, testing every 24 to 48 hours is suggested, she said, according to the Los Angeles Times.

California reported a 11.4 percent positivity rate on Wednesday.