Coronavirus Test Result Delays Hinder Contact Tracing
In early July, Talia Landerman decided to get a coronavirus test.
This was when Allegheny County was reporting nearly 200 cases of COVID-19 daily. Landerman works in an office and both her parents are over 60, so she wanted to be sure she wasn't an asymptomatic carrier.
Because she didn’t have symptoms or known exposures, Allegheny Health Network and UPMC wouldn’t test her, so Landerman decided to go to one of the free CVS drive through testing sites.
“The line literally went around the entire building,” she said.
After waiting almost an hour, it was finally Landerman's turn to submit a sample, which she collected herself.
“I had to insert the nasal swab [to] what it felt like to my brain cavity. Which I know it wasn’t, but it went in there pretty far,” she said.
CVS provides PCR tests, which experts say are the least likely to produce a false negative. Landerman said her sample was sent to Quest Diagnostics, a national lab that analyzes tests from all over the county, including hot spots like Florida and Texas. This causes bottlenecks. Landerman said she waited nearly two weeks for her results, which were negative. But had she tested positive, from a public health standpoint, that’s pretty useless.
“The faster you can get the test results, the more capable your contact tracing programs will be at stopping the spread of an outbreak,” said Dr. Mark Roberts, chair of the Department of Health Policy and Management at the University of Pittsburgh Graduate School of Public Health.
The more quickly contact tracers begin their work, the more quickly people who may have been exposed know to quarantine. On the flip side, delays allow the virus to spread to others.
“Those other people have no knowledge that they might have been exposed,” said Roberts.
On July 23, the Allegheny County added a new line to its daily report of new coronavirus cases: "The date of positive tests ranged from July 6 through July 22." Typically these ranges were about three weeks, but occasionally, the ranges ballooned to a month or more. The day after WESA inquired about whether the lag time in reporting test results was blurring the picture of COVID-19 spread in Allegheny County, the daily e-mails began to include information about what proportion of cases were from specimens collected more than a week or two prior.
County data show that tests results are returning more quickly compared to last month. And even at the height of Allegheny County’s outbreak not everyone was waiting weeks for results.
“The lag time ... is a minority of the cases," said Dr. Debra Bogen, director of the Allegheny County Health Department. "Most of the tests are being sent to local labs and coming back quickly enough that our confidence in our numbers is good."
This includes tests conducted by Allegheny Health Network and UPMC, which have their own facilities to analyze samples.
Cases investigators report that more than half of people who contract COVID-19 have no idea how they got it. That’s in part because many people infected with the coronavirus don't have symptoms. The Squirrel Hill Health Center, which provides a test to anyone who requests one, reports that 40 percent of its positive cases are asymptomatic.
“The broader your testing approach the more likely you’re able to identify where transmission is occurring, and direct your public health resources to try to reduce transmission,” said Josh Michaud, a global health policy expert at the Kaiser Family Foundation.
Ideally everyone would be tested for COVID-19 regularly. But due to a lack of a national testing strategy, there’s a confusing patch work of providers who each have their own criteria for who gets tested and which tests are prioritized. When added to international supply chain shortages, people like Talia Landerman just aren’t a priority.
This results in undiagnosed, asymptomatic people spreading the virus.
“Which makes it hard to have public health interventions which actually interrupt the transmission,” said Michaud.
There are a couple lesser known options for testing. Federally Qualified Health Centers in Allegheny County are more likely to test anyone, regardless of symptoms or exposure. Results are usually back in few days.
Some urgent care facilities now provide rapid antigen tests which produce results in about 20 minutes, but are less accurate
In the meantime, scientists expect COVID-19 cases to spike again due to cold weather and school resuming, which will likely cause testing bottlenecks to worsen in the coming months.