To Speed Up Results, States Limit COVID-19 Testing
Read Stateline coverage of the latest state action on coronavirus.
Dr. Karen Landers, Alabama’s assistant state health officer, has never had a COVID-19 test and doesn’t plan to get one unless she gets sick.
She’s urging all Alabamians to do the same.
“Don’t get up in the morning and say, ‘I think I’ll go get a test just to see what it shows.’ You need to have a good reason,” she said in an interview with Stateline. “Even if you’ve been in close contact with someone who tested positive, you don’t necessarily need a test. You need to home-quarantine for the number of days recommended — generally up to 14 days from the last exposure to the case.”
Limits on testing are anathema to epidemiologists. If enough tests were available and results weren’t delayed as they are now, Landers and other health officials would insist on testing at least twice as many people as they’re testing now.
But that’s not realistic in Alabama or most of the rest of the country.
Most results are taking much longer than the two-day turnaround epidemiologists say is needed to be effective in stopping the spread.
As a result, some states are starting to limit the number of tests they conduct to give labs a chance to catch up on their backlogs and deliver results quickly enough for health departments to tell people to quarantine and to trace their contacts.
California’s secretary of health, Dr. Mark Ghaly, announced new testing guidelines in mid-July. He said the state would start prioritizing patients who were hospitalized with symptoms as well as those in vulnerable populations, until testing turnaround times improve.
Other states including Michigan, Minnesota and Virginia also are recommending new testing priorities.
In Alabama, Landers was blunt: Unnecessary testing needs to stop.
“We need to use our statewide testing resources wisely and only test people who have appropriate reasons to be tested,” she told Stateline. “That’s a limited prescription, but that’s all I have right now.”
The number of COVID-19 tests conducted every day in the United States has risen exponentially since March. In total, the United States has conducted more tests than any other country in the world.
But as hundreds of thousands of samples are collected every day in hospitals, outpatient clinics and sweltering parking lots, the specialized laboratories that analyze the samples have become so backlogged that results are delayed by as much as two weeks.
“Naturally you want to do more testing because you want to get a handle on what’s going on right now,” said Scott Becker, CEO of the Association of Public Health Laboratories. “But we’re struggling in the lab community because the supply issues that have plagued us from the beginning haven’t gone away.
“There’s no real value in testing if you’re not getting results in a timely manner to take action. If you’re potentially exposed, you need to stay home. The only way we’re going to get out of this with the shortages we’re seeing goes back to individual behaviors — masks, hand hygiene and not going to large gatherings.”
Working around the clock, public and commercial labs already have scaled up to their maximum capacity, Becker said. Any further increases in capacity are going to be incremental until next year, he said.
The tests currently offered at drive-thru sites and in most medical facilities are typically polymerase chain reaction or PCR tests. They are the most accurate type of test available, and under normal circumstances, results can be available in less than 24 hours.
But since June, backlogs at the nation’s labs have grown, creating an average wait time of more than four days, according to a survey published in August by researchers at Harvard Medical School, Northeastern University and Rutgers University.
“When you have tests that take that long, you have no choice but to prioritize,” said Dr. Jennifer Nuzzo, senior scholar at the Johns Hopkins Center for Health Security. “The most important metric that we’re not following is test turnaround times.”
To be effective, COVID-19 test results should be available within 48 hours, preferably 24 hours, Nuzzo said. “Any more than that hinders contact tracing and leads to future case growth because you can’t intervene to interrupt transmission.”
Another, less accurate type of test, called an antigen test, can provide nearly instant results and can be mass produced. Since the test does not require laboratory analysis, it ultimately could allow people to cheaply self-administer a COVID-19 test at home.
Ten states — Arkansas, Louisiana, Maryland, Massachusetts, Michigan, North Carolina, Ohio, Rhode Island, Utah and Virginia — have banded together to acquire 5 million of these quick turnaround test kits, to reach people who are asymptomatic and could be unknowingly spreading the virus. Ultimately, the group hopes to purchase 100 million kits.
More states are expected to join the group in the weeks ahead, said Eileen O’Connor, senior vice president for communications, policy and advocacy at the Rockefeller Foundation, which is supporting the states. But she said the cheaper, faster tests won’t be available for at least a month.
In March, when the COVID-19 battle began, epidemiologists were hobbled by a severe shortage of swabs and other testing materials. Only people with symptoms could get tested, and there weren’t even enough tests for everyone who was sick or hospitalized.
Later, testing capacity picked up and governors started touting higher daily testing numbers and more liberal testing criteria. President Donald Trump repeatedly maintained that anyone who wanted a test could get one.
Nearly 64 million tests later, the nation still lacks enough tests to control the virus.
On average, fewer than 700,000 Americans were tested per day in the past week, according to the COVID Tracking Project, and 7.8% of the results were positive. Before reopening schools and businesses, the World Health Organization has recommended a 5% or less positivity rate with adequate testing capacity.
To achieve that, the Harvard Global Health Institute currently recommends the United States conduct at least 4 million tests a day, a number that changes over time based on the number of positive cases per capita.
A new Rockefeller Foundation report recommends the nation ramp up testing to 5 million two-day PCR tests and 25 million antigen tests a week over the next three months.
“We’re still in this model of working to get more tests,” Nuzzo said. “But in the meantime, we want to make sure the tests we’re doing are meaningful.”
New studies show that at least 40% of people infected with the virus have no symptoms, but they can infect others for up to 10 days after contracting it.
As schools, universities and businesses reopen, they are increasingly demanding screening tests for students, teachers and employees who are not exhibiting symptoms but could spread the virus.
But until more tests are available, and unless the organizations can supply their own tests conducted in laboratories not used by the general public, some states are recommending against that type of surveillance testing.
Here are California’s recommended testing priorities, which are similar to those in Alabama and other states:
The first people tested should be patients entering a hospital with COVID-19 symptoms and people involved in specific outbreaks that a state or local health department is investigating.
After that, anyone with symptoms, as well as asymptomatic people who live or work in high-risk environments — including nursing homes, jails, homeless shelters and other congregate settings, plus health care workers, police and other frontline workers – should be tested on a regular basis.
A third priority is people who work in public-facing jobs, including retail and food service employees, transit workers, teachers and agricultural and food processing workers.
Finally, when enough tests are available to test everyone in the top priority groups and give them results within 48 hours, anyone who believes they may have been infected should be able to seek a test.
Last month, the federal Centers for Disease Control and Prevention recommended against retesting individuals who have been quarantined to determine whether they are still infectious. The agency said substantial scientific research definitively shows that people infected by the virus with mild to moderate symptoms are only contagious for up to 10 days.
In Alabama, Landers tells patients who want a test so they can safely visit an elderly family member to do a virtual visit instead. If that doesn’t work, she explains that even the most accurate COVID-19 test is only a snapshot. A person could get tested too early, fewer than three days after exposure, and the virus wouldn’t show up. And someone could get a negative test and be exposed the very next day.
If an in-person visit is necessary, Landers says, she tells patients to get tested and quarantine at home until they receive the results. “Then, if you need to travel, be very careful. It’s a message we keep repeating.”