Turnaround times for coronavirus tests are on the rise again.
Amid a record demand for testing ahead of the Thanksgiving weekend, Quest Diagnostics said this week that it’s taking up to three days to complete a test after receiving a sample. LabCorp, another large private lab company, said higher testing demand means it now takes up to two days to complete a test.
These turnarounds don’t include the time it takes a person to schedule and get a test at a doctor’s office, urgent care facility or other sites. Several sites across the nation this week had long lines of people waiting to get tested.
The delays have not reached this summer’s levels when overwhelmed labs took a week or longer to get results, making tests of little use to people who might have unwittingly spread the virus to others.
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Labs are completing more COVID-19 tests than ever as cases and hospitalizations surge nationwide. People are seeking tests after developing symptoms, being exposed to others sickened by the virus, or traveling over the holiday. Over the past week, nearly 1.8 million U.S. tests have been performed every day – the highest one-week average since the pandemic began, according to COVID Tracking Project.
But there are worrisome signs the testing upswing has unleashed a global competition for limited supplies of chemicals and containers needed to perform these tests. If labs can’t get enough reagents or disposable dispensers, it could further delay tests.
“I’m very afraid there is going to be a shortage of testing materials,” said Dr. Patrick Godbey, laboratory director of Southeast Georgia Regional Medical Center in Brunswick.
He said his lab can’t get enough chemical reagents to complete timely tests for a nursing home affiliated with the hospital. That means the lab must send samples via courier to outside labs. And each extra step delays results.
“If I have to send it away to a reference lab like Quest or LabCorp, we start measuring turnaround times in days rather than hours,” Godbey said.
Labs add capacity, prioritize sicker patients for testing
Julie Khani, president of the American Clinical Laboratory Association, warned earlier this month that suppliers are canceling or delaying orders on materials, such as pipette tips, needed to complete tests.
“The surge in demand for testing will mean that some members could reach or exceed their current testing capacities,” Khani said.
On Tuesday, Quest said in a statement the company is adding testing machines and equipment to expand overall capacity and is communicating with testing suppliers. The lab also prioritizes tests for people who are hospitalized, awaiting surgery, or in nursing homes.
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Because cases are so widespread, labs can no longer rely on a method of conserving supplies by testing multiple samples at once. If the test finds no signs a pooled sample contains the coronavirus that causes COVID-19, the group of people tested are considered negative. A positive result requires each sample to be tested individually.
It was a shortcut that allowed labs to save on reagents and disposable containers when the virus was at low levels. But Khani said pooled sampling is limited because the share of positive tests is increasing in communities across the country.
With more than 88,000 in hospitals and over 2,100 Americans dying each day, public health officials urge people to wear masks, distance themselves from others and wash their hands.
The Centers for Disease Control and Prevention also has advised families to avoid travel during Thanksgiving and limit gatherings to people you live with. Despite the warnings, Americans were still traveling. Sunday was the busiest day at airport checkpoints since March.
Even before warnings that holiday travel would lead to a spike in cases, labs were taking steps to handle the increased workload.
Some hospital labs have stopped doing tests for sexually transmitted diseases such as chlamydia and gonorrhea because those tests use the same materials needed to run COVID-19 tests, Godbey said. Hospital labs have tried to find smaller, private labs to handle those tests, resulting in delayed results.
“We do not have enough reagents. We do not have enough (disposable supplies) such as tips,” Godbey said. “What that means is we will have to choose. Does this person need this test done locally? Do we have to send it away? How quickly do we need to make that medical decision?”
Americans must ‘act like we’re in a war’ against coronavirus
Other experts say the testing crunch is a result of the nation’s over-reliance on the most common type of test, called a polymerase chain reaction, or PCR, which amplifies a small amount of genetic material from a nasal swab sample. PCR tests are considered the most sensitive and pick up small amounts of the virus, but most PCR tests must be done in a lab.
Antigen tests, which detect proteins of the virus, are less expensive and deliver results in less than one hour. These tests can be performed outside a lab on instruments used at doctors’ offices, urgent care facilities or nursing homes.
The U.S. Department of Health and Human Services has purchased antigen testing machines and sent them to more than 15,000 nursing homes. HHS also purchased 150 million rapid antigen test cards called BinaxNOW, made by Abbott Laboratories. Nearly 40 million BinaxNOW cards have been sent to states and 24 million sent to nursing homes, tribes, historically Black colleges and universities and others, according to HHS.
Michael Mina, a Harvard epidemiologist, has advocated for creating a national strategy to promote more widespread use of rapid antigen tests. Although antigen tests are less sensitive than lab-based PCR tests, Mina argues if used frequently they can detect when a person is infectious and more likely to spread the virus to others.
“Very few of them are being used because there’s been no strategy,” Mina said.
Mina said a national strategy could make lab and antigen testing “much, much more useful. We’d also start to see PCR testing not be backed up so much because we could start actually replacing some of that PCR testing with rapid testing.”
Though several companies are studying home-based antigen tests in clinical trials, none has been authorized by the Food and Drug Administration.
Mina predicted the nation could effectively control the spread of the virus within two months if Americans took these home tests twice a week – and isolated from others when infected.
“We just need to act like we’re in a war,” Mina said. “We need to have leadership at the state and federal level that are just willing to think about this as a war. … We have tools. These are our weapons right now that can be available.”
Ken Alltucker is on Twitter as @kalltucker or can be emailed at firstname.lastname@example.org