WASHINGTON – After struggling to ramp up coronavirus testing, the U.S. can now screen several million people daily, thanks to a growing supply of rapid tests. But the boom comes with a new challenge: keeping track of the results.
All U.S. testing sites are legally required to report their results, positive and negative, to public health agencies. But state health officials say many rapid tests are going unreported, which means some new COVID-19 infections may not be counted.
And the situation could get worse, experts say. The federal government is shipping more than 100 million of the newest rapid tests to states for use in public schools, assisted living centers and other new testing sites.
“Schools certainly don't have the capacity to report these tests,” said Dr. Jeffrey Engel of the Council of State and Territorial Epidemiologists. “If it's done at all it's likely going to be paper-based, very slow and incomplete.”
Early in the outbreak, nearly all U.S. testing relied on genetic tests that could be developed only at high-tech laboratories. Even under the best circumstances, people had to wait about two or three days to get results. Experts pushed for more point-of-care rapid testing that could be done in doctors offices, clinics and other sites to quickly find people who are infected, get them into quarantine and stop the spread.
Beginning in the summer, cheaper, 15-minute tests – which detect viral proteins called antigens on a nasal swab – became available. The first versions still needed to be processed using portable readers. The millions of new tests from Abbott Laboratories now going out to states are even easier to use: they're about the size of a credit card and can be developed with a few drops of chemical solution.
Federal health officials say about half of the nation's daily testing capacity now consists of rapid tests.
Large hospitals and laboratories electronically feed their results to state health departments, but there is no standardized way to report the rapid tests that are often done elsewhere. And state officials have often been unable to track where these tests are being shipped and whether results are being reported.
In Minnesota, officials created a special team to try to get more testing data from nursing homes, schools and other newer testing sites, only to be deluged by faxes and paper files.
Even before Abbott's newest BinaxNOW rapid tests hit the market last month, undercounting was a concern.
Competitors Quidel and Becton Dickinson have together shipped well over 35 million of their own quick tests since June. But that massive influx of tests hasn't showed up in national testing numbers, which have mostly ranged between 750,000 and 950,000 daily tests for months.
Besides tallying new cases, COVID-19 testing numbers are used to calculate a key metric on the outbreak: the percentage of tests positive for COVID-19. The World Health Organization recommends countries test enough people to drive their percent of positives below 5%. And the U.S. has mostly been hovering around or below that rate since mid-September. The figure is down from a peak of 22% in April.
But some disease-tracking specialists are skeptical. Engel said his group's members think they aren't getting all the results.
“So it may be a false conclusion,” he said.
Over 1,600 cases added to state count
The Indiana Department of Health announced 1,629 additional Hoosiers were diagnosed with COVID-19 through testing Sunday. That brings to 147,582 the number of Indiana residents known to have the novel coronavirus.
A total of 3,704 Hoosiers are confirmed to have died from COVID-19, an increase of 19 from the previous day. Another 233 probable deaths have been reported based on clinical diagnoses in patients for whom no positive test is on record.
To date, 1,555,437 unique individuals have been tested in Indiana, up from 1,545,927 on Saturday. A total of 2,512,174 tests, including repeat tests for unique individuals, have been reported to the state Department of Health since Feb. 26.
Another 88 Allen County residents tested positive for COVID-19, with 73 confirmed PCR cases and 15 probable antigen cases, bringing the total to 7,791 cases and 213 deaths Sunday, according to the Allen County Department of Health.
The Allen County case count now includes 705 probable cases from antigen tests reported since July 28.
– Staff, news services