The Trump administration official in charge of the United States’ COVID-19 test strategy said Thursday’s backlog is improving and that most laboratory results are returning in three days or less.
Outbreaks of COVID-19 in the south and west have reduced the capacity of laboratory tests, leading to response times of several days or even weeks, hindering efforts to contain the spread of the virus.
Over the past seven days, 56 percent of the COVID-19 tests had a response time of three days or less, which Undersecretary of Health Admiral Brett Giroir characterized as an improvement.
Over the past month, 45 percent of test results returned from commercial labs in three days, he said.
“We are seeing improvement week after week,” Giroir said in a call with journalists, adding that response times of 10-14 days are “outliers.”
“I hope it will improve markedly in the next two weeks,” he added.
Giroir said the administration is working with commercial labs to prioritize faster results for people in nursing homes, hospitals, and people who are supposed to have COVID-19.
Experts say response times should be as fast as possible to contain the outbreak. While public health officials say people should isolate themselves while waiting for their test results, there is little data to indicate how often that happens. Longer response times run the risk of making someone less likely to isolate themselves, especially if they don’t experience any symptoms.
Long response times also make it much more difficult to quickly assess, trace and isolate the contacts of people who tested positive for COVID-19, at the risk of those people spreading the virus in their communities.
Commercial labs like Quest and LabCorp perform about half of the COVID-19 tests in the U.S.
Response times at Quest, one of the largest commercial labs in the US, are more than two days for priority 1 patients (hospital patients and asymptomatic healthcare workers) and seven days for all others, the company stated in an update released on Wednesday.
“Persistent high demand has exhausted our testing capacity and has extended delays in testing results,” the update says.
“We hope that as our capacity continues to grow, we can return to average response times in the range of 1 day for priority 1 patients and 3 days for most other patients.”
LabCorp response times are two to three days from sample collection, but are “faster” for hospitalized patients, according to an update released this week.
“We continue to focus on reducing the time it takes for a patient to receive their result, and as additional equipment and supplies become available, we expect the average time to improve,” says the update.
Point-of-care tests, which return results in about 15 minutes, are becoming increasingly available, but they are sent primarily to nursing homes, where residents are at increased risk of serious illness and death.
“Right now, everything that comes off the line in terms of new instruments is being shipped to nursing homes,” said Giroir.
Giroir has said he hopes the increased availability of those tests will ease the strain on commercial labs.
Some experts argue that the Food and Drug Administration (FDA) must approve tests that are less sensitive than tests that must be sent to a laboratory.
Currently, the FDA requires that COVID-19 tests have a minimum sensitivity of 80 percent, which means that it could throw false negatives 20 percent of the time.
Experts argue that lower sensitivity tests return results faster and can be done at home and still detect many infections.
“By putting a prize on test accuracy, we are unable to assess most people with COVID-19, and these built-in delays actually undermine our ability to identify cases early, which is the key purpose for widespread testing. “, Dr. Ashish Jha, professor of global health at Harvard TH Chan School of Public Health, wrote in a TIME opinion piece published on Wednesday.
“If everyone had an antigen test today, even identifying only 50 percent of positives, we would still identify 50 percent of all current infections in the country, five times more than the 10 percent of cases that are likely we are currently identifying because we are testing too few people. “
Giroir said Thursday that some of the less sensitive tests may be helpful in some situations, but provide a false sense of security in others. For example, he said that some tests have a sensitivity of 20 to 30 percent, which means they miss infections 70 to 80 percent of the time.
“I am sure that as more things get closer to the market that are not in the 20-30 percent sensitivity range, but are in the 70-80 percent range, then we have to understand where it fits into the ecosystem generally where it might be useful and where it might not be, “he said.
“I don’t think that would do a service to the American public by having something that is wrong 7 out of 10 times and could potentially give someone a false sense of security that they are negative,” Giroir said.
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