Testing delays once again hamper COVID-19 response
Surging COVID-19 outbreaks in several states are straining testing capacity across the country as people wait several days or even weeks to get their results back, causing another setback to the U.S. response to the months-long pandemic.
Lengthy turnaround times are undermining the fight against the coronavirus, experts say, making efforts to trace contacts of confirmed cases almost pointless. That, in turn, potentially leads to more infections that threaten to strain testing capacity further.
“The concern is it’s just starting to spiral out of control,” said Marcus Plescia, chief medical officer at the Association of State and Territorial Health Officials.
While public health officials say people should be self-isolating while they wait for their test results, there’s little data to indicate how often that’s happening. Longer turnaround times run the risk of making it less likely someone will self-isolate, especially if they’re not experiencing any symptoms.
“It really undermines our infection control,” Plescia said. “Somebody who has COVID but has less typical symptoms or doesn’t feel that bad, they may feel like it’s probably not COVID, and they’ll be going out in public. And if it turns out they really do have COVID, they could have infected significant numbers of people.”
Large outbreaks in Florida, Texas, California, Arizona and Georgia have overwhelmed private labs like Quest Diagnostics and LabCorp, leading to slower turnaround times. Some states with smaller case numbers are even seeing delays.
While commercial labs have significantly increased the capacity for testing since the early days of the pandemic, there is still not enough to handle the increased demand.
Congress has appropriated $25 billion to improve testing and contact tracing, but none of that has gone to commercial labs that are bearing the brunt of testing.
“It’s the demand that’s changed very, very significantly,” said a spokesperson for the American Clinical Laboratory Association, which represents clinical laboratories like Quest and LabCorp.
“Labs across the board are seeing significantly increased testing demand and constraints in the availability of supplies and equipment.”
Quest Diagnostics, the largest lab in the U.S., says the turnaround time for “priority patients” — symptomatic health care workers and hospitalized patients — is about two days. The turnaround time for everyone else is more than seven days or up to two weeks.
LabCorp on Monday said the average turnaround time is now between three and five days, though some people have waited longer for their results.
“The value of a test that comes back even five days later is very little,” said Tom Frieden, director of the Centers for Disease Control and Prevention during the Obama administration.
“People are most infectious both about the two days before they get sick, and maybe three or four days after they get sick. So if you’re telling someone they were infected five days after they felt sick, they’ve already infected most of the people they’re going to infect. And those people have already potentially become infected as well.”
The delays have had a negative impact on contact tracing, the process public health officials use to try to break the chains of transmission by contacting people who test positive and asking them to quarantine while tracers reach out to their close contacts to get them tested, also asking them to self-isolate while they await results.
“Some states and communities are sort of wondering if there’s a little bit of futility in trying to do any contact tracing,” Plescia said.
Contact tracing requires quick test results, especially for COVID-19, which spreads easily and exhibits no symptoms in a large percentage of carriers. People who are asymptomatic can still transmit the disease to others.
“Until you know the results of somebody’s test, you can’t really find out who their contacts are and contact those people and tell them that they may be infected as well,” Plescia said. “A lot of state and locals [governments] are very concerned that they’re missing the window of opportunity for where their contact tracing can make the difference.”
The surge in cases and increased demand for testing has renewed calls for a national testing strategy from the Trump administration.
Labs still don’t have enough supplies needed to run tests in high volumes, and as demand grows, some labs are finding they need more machines that are also in short supply.
President Trump briefly addressed the issue on Tuesday.
“We’re also working to reduce turnaround time,” Trump said during a press briefing at the White House, but did not elaborate.
“We’ve done more testing than anybody. Some of the tests, because it is a massive volume, it takes longer. Other tests, as you know, are very quick. They’re five minutes and 15 minutes tests and those are the ones I prefer.”
The administration has mostly let states set their own testing goals, even though some of the largest labs have operations across the country.
“Unquestionably, we need a national testing strategy that does not simply provide each state with the ability to define what’s best for them,” said Heather Pierce, senior director of science policy and regulatory counsel for the Association of American Medical Colleges.
“States are essential partners, but in terms of understanding reagent shortages and prioritizing where reagents and test supplies go, that should be done on a national comprehensive level,” she added.
Trump administration officials acknowledged the slower turnaround times in a call with governors this week, with Adm. Brett Giroir saying it would put a greater focus on point of care tests that can be done in 15 minutes at a patient’s bedside or doctor’s office.
The Department of Health and Human Services (HHS) plans to send point-of-care test instruments and kits to all 15,400 nursing homes in the U.S., potentially freeing up some capacity at commercial labs. However, HHS noted that it is a one-time shipment, and nursing homes will need to find their own test kits after that.
The Food and Drug Administration also recently approved a request from Quest to “pool” tests, in which samples from several patients are combined and then tested together instead of individually.
Patients in pools that test positive for COVID-19 are then individually tested, while negative pools are cleared. The goal of pool testing is saving time and limited resources.
However, experts say these efforts are unlikely to be useful in hot spots or settings like nursing homes or prisons, where the virus spreads at a furious pace. The pooling approach might be more useful as a surveillance tool, they said, to quickly identify where new cases are occurring.
Experts think some states might need to go back to prioritizing tests for certain populations, like hospitalized patients and close contacts of confirmed cases, in order to decrease turnaround times.
“I think there’s just no doubt about it that we don’t have as many tests as we need — let’s be frank about that. And, therefore, we’re going to have to prioritize and determine which patients should get them first and which patients to get which tests,” Frieden said.
“Prioritization can help a lot. Unless we have test times down, we’re not going to get ahead of the virus.”