Jan 11, 2022 - COVID

Colorado doesn't count results from at-home COVID tests

An at-home COVID swab casting a shadow in the shape of a question mark.
Illustration: Maura Losch/Axios

As America's record Omicron surge continues, states have no cohesive strategy to monitor the results of at-home rapid COVID-19 tests.

  • However, those results are not included in the state's official positivity rate, Axios has learned.

Why it matters: The patchwork system means the official COVID case tally is certainly an undercount.

  • Many states and cities don't have an accurate sense of just how prevalent the virus is as they make decisions about mask mandates, school closures and other restrictions.

Zoom in: Colorado's positivity rate only includes PCR and other molecular tests, not positive or negative antigen rapid tests — even those conducted by medical providers, said Kristen Stewart, a state spokesperson.

Still, the state wants people to report positive results to their doctors, or state and local public health agencies.

  • An infected individual who reports a positive test is entered into the state's disease surveillance system for possible investigation and contact tracing.
  • The state has received nearly 350,000 reports of positive tests so far, but couldn't specify how many were conducted.

Between the lines: Rapid tests "have their place," Rachel Herlihy, the state's epidemiologist tells Axios. "But we know that they are not always reported to public health officials, so there can be a little gap in our knowledge."

The big picture: Rapid tests are already in short supply, and a small preprint study released this week found that people may not test positive with them until after they're infectious, which would make at-home test results an unreliable measure of whether it's safe to gather, as Axios' Caitlin Owens reported.

  • "Based on viral load and transmissions confirmed through epidemiological investigation, most Omicron cases were infectious for several days before being detectable by rapid antigen tests," the study's authors wrote.

The bottom line: Omicron may have exposed the limitations of at-home rapid tests — not only as a gauge of how big the current case surge truly is, but also as a possible pathway to avoid COVID disruptions in daily life.

Go deeper: The response in other states


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