New self-administered COVID-19 swab tests hold promise for wide-scale testing at home

This week, as lines lengthen at COVID-19 testing sites, Florida’s nursing homes and assisted living facilities begin state-mandated, bi-weekly testing of all employees. In the process, the innovative way those tests will be conducted could set the stage for wide-scale at-home testing.

That statewide screening of long-term care facilities, critically important as the number of cases in the public at large is soaring, is being entrusted to a single California-based start-up with a much simpler means of collection – a self-administered swab of the mouth.

The oral-fluids test developed by Curative Inc. is one of the very few oral-swab tests approved for emergency use by the FDA. Founded just months ago by a 24-year-old Oxford University drop-out, Curative and partner KorvaLabs were selected to universal test Los Angeles County. The company has since won contracts with the U.S. Air Force, Florida and Alaska.

Florida’s Division of Emergency Management selected Curative, which supplies not only test kits but software and video training. In the previous mass testing of long-term care staff and residents, facilities were given a list of state-approved labs to choose from.

The test involves coughing several times first, then swabbing around the mouth for 20 seconds before dropping the swab into its container of stabilizing medium.

So far, no mandate has been issued to repeat mass testing of residents in the facilities, though CDC guidelines require daily COVID-19 symptom checks. If a resident tests positive, it is considered an outbreak, and mass testing must follow, according to guidelines.

Without regular mass screening of residents, the many asymptomatic cases that turned up in the original mass test will be missed, and those cases can spread the disease if they are not identified and isolated.

Just as important, results must be returned quickly so isolation of positives can begin immediately. In Vero, several facilities waited for results longer than the quarantine period of 14 days, meaning whoever had been positive and asymptomatic may well have cleared the virus in the meantime.

In mid-May, AdventHealth, a prominent Central Florida health system, canceled its contract with an unnamed lab after 33,000 results from a Texas-based lab, MicroGen DX, turned out to be unreliable or were trapped in a backlog.

MicroGen DX’s CEO, Rick Martin, said the company had agreed to a 48- to 72-hour turnaround time, but admitted that stretched to 10 to 12 days. Martin told the Orlando ABC television affiliate that test samples had sat around for two to three days at room temperature.

The mass testing of nursing homes and assisted living facilities that took place in May and June turned out to have huge delays in getting results back. In Indian River County alone, several facilities saw delays of two weeks to more than a month.

With the new mandate of bi-weekly staff testing, the Division of Emergency Management has stipulated a turnaround time of 48 hours. The test kits will be delivered directly to facilities by mail or courier, and the facilities will use a pre-addressed shipping label to mail the specimens to the lab.

The false negative rate for the Curative swabs is 10 percent, which the company says is “at least as good” as standard nasopharyngeal swabs. In terms of sensitivity to the virus – key to finding all the positives – oral-liquid swab tests have 90 percent sensitivity compared to 79 percent for nasal swabs. That’s because the capture method retrieves virus from two areas – the lungs and the mouth.

The long-term care facilities will get enough test kits for two rounds of testing – a one-month supply. The state requires that the oral-liquid swab must be done at the facility, and in accordance with the FDA emergency rule, the swabbing must be supervised, though the person watching doesn’t have to be a nurse.

If the testing goes smoothly, the effort would prove the oral-liquid swab could be done in a wide range of facilities and could even propel Curative into the much-needed home market, with telehealth providing the FDA-required supervision of the swabbing.

Curative began as a sepsis testing company, founded in January by Fred Turner, who had just arrived in Silicon Valley from the U.K., where he had worked in agricultural genetics research.

In late February, hearing of the shortage of diagnostics in the pandemic, Turner pivoted to COVID-19 testing. Partnering with a sports drug-testing lab called KorvaLabs, Curative began working exclusively on COVID-19 tests.

In 10 days, the company had developed an assay, and within four weeks, they were processing 5,000 tests a day. By the beginning of June, Turner’s company was doing 25,000 tests a day.

Turner believes self-administered tests are the only way to achieve the high volume required to open the nation fully. “There’s just no way we’re going to do a million nasal pharyngeal swabs – we just call them brain swabs. We don’t have the medical staff, and as a country we just can’t do that many swabs,” Turner said. “The only way forward is self-collection. We’re not using PPE, and we’re not exposing healthcare workers.”

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