More than 20 states either don't release or have incomplete data on the rapid antigen tests now considered key to containing the coronavirus, which has sickened more than 6 million Americans. The lapses leave officials and the public in the dark about the true scope of the pandemic as untold numbers of cases go uncounted.
The gap will only widen as tens of millions of antigen tests sweep the country. Federal officials are prioritizing the tests to quickly detect COVID-19's spread over slower, but more accurate, PCR tests.
Relying on patchy data on COVID-19 testing carries enormous consequences as officials decide whether to reopen schools and businesses: Go back to normal too quickly and risk even greater outbreaks of disease. Keep people at home too long and risk an even greater economic crisis.
"The absence of information is a very dangerous thing," said Janet Hamilton, executive director of the Council for State and Territorial Epidemiologists, which represents public health officials. "We will be blind to the pandemic. It will be happening around us and we will have no data."
The states that don't report antigen test results or don't count antigen positives as COVID-19 cases are California, Colorado, Georgia, Illinois, Maryland, Minnesota, Missouri, Montana, New Hampshire, New Jersey, North Carolina, North Dakota, Ohio, Pennsylvania, South Dakota, Tennessee, Texas, Vermont, Virginia, Washington, Wisconsin and Wyoming, as well as the District of Columbia.
So far, most of the COVID-19 tests given in the U.S. have been PCR tests, which are processed in medical labs and can take days to return results. By contrast, antigen tests offer results in minutes outside of labs, appealing to everyone from medical clinics to sports teams and universities.
Each relies on swabs to test patients. But unlike using tests run through labs, many providers who would use antigen tests don't have an easy way to send data electronically to public health authorities.
Since July, though, the federal government has pushed roughly 5 million antigen tests into nearly 14,000 nursing homes to contain outbreaks among staff members and residents. The Department of Health and Human Services also awarded a $760 million contract to buy 150 million rapid antigen tests from Abbott, the Illinois-based diagnostics behemoth. It plans to send 750,000 of those to nursing homes starting this week, Brett Giroir, the HHS official heading the Trump administration's testing efforts, told industry executives on Sept. 8. Federal officials have not elaborated on how many tests will be sent elsewhere but have suggested many will go to governors to distribute as schools reopen.
The rush of antigen tests, however, won't be particularly useful to officials if the results are not publicly and uniformly reported.
KHN surveyed 50 states and the District of Columbia on their collection of antigen test results and what is reported publicly. Forty-eight responded between Sept. 3 and 10, revealing significant variation over whether people who test positive for COVID-19 with an antigen test are counted as cases and whether states even publicly report antigen data in their testing numbers: