A number of states are not including positive results from rapid COVID-19 testing in their case numbers, the Verge reports.
Kaiser Health News surveyed US states and the District of Columbia regarding their collection and reporting of antigen test results. Most tests for COVID-19 in the US are PCR based, processed in labs, and results can take days, but rapid antigen tests can be done outside of the lab and return results within minutes, the Verge notes. Such rapid tests, though less sensitive than PCR tests, have been implemented, for instance, at nursing homes.
According to Kaiser Health News, 48 states and the District of Columbia responded to its survey, which found that 22 states and DC don't report antigen test results or don't count positive antigen tests as COVID-19 cases. This, it says, means that state case numbers could be too low.
Part of the issue, Kaiser Health News notes is that Centers for Disease Control and Prevention guidelines define a "confirmed" COVID-19 case as one that is detected by PCR, while positive antigen test is considered a "probable" COVID-19 case. "It's easy for people to think since we use the word 'probable' that maybe it's a case, maybe it isn't. But that's not how we think of it," Jennifer Dillaha, state epidemiologist for the Arkansas Department of Health, tells Kaiser Health News. "It is a real case in the same way that a PCR is a real case.