Utah halts rapid tests amid concerns about false negatives

February 7, 2022 GMT

SALT LAKE CITY (AP) — Utah will no longer offer residents rapid COVID-19 tests after an analysis showed one brand of nasal swabs used at state mobile clinics often yielded false negatives.

State health officials said Sunday that they had analyzed the results from 18,000 people who had received traditional PCR tests and rapid tests manufactured by GenBody. More than half the times a PCR test came back positive, the GenBody swab yielded a negative result.

“While rapid antigen tests are known to be less likely to identify a positive individual, the difference identified in this analysis was higher than expected,” the department said.

Reports of the false negatives came as the United States experiences an omicron variant-fueled surge, causing cases, hospitalizations and deaths to spike. In Utah last month, COVID-19 hospital admissions hit an all-time high of 125 on Jan. 18.

The rapid antigen tests, designed to detect the presence of viral proteins rather than the coronavirus itself, return results in minutes, unlike traditional molecular tests sent to labs, which can take days to process but are shown to be more accurate.

Their quick turnaround times have led to their widespread use in prisons, schools and nursing homes.

Federal health officials have said their research shows rapid tests can be even less accurate at detecting the omicron variant. But Leisha Nolen, Utah’s state epidemiologist, told The Salt Lake Tribune that the false negatives didn’t appear to be correlated with variants.

The state continues to use Abbott’s BinaxNOW tests, which the federal government provides to states to be used in high-risk settings where routine testing is recommended.

The state’s analysis found the BinaxNOW tests yielded less false negatives than the rapid tests manufactured by GenBody, officials said Sunday.