Tennessee began reporting a new set of COVID-19 numbers this week that indicate a significant, if somewhat confusing, shift in efforts to slow the spread of the highly infectious and resurgent disease.
For the first time, the state health department is reporting the opens in a new windownumber of people who have received PCR lab tests and antigen “rapid” tests (positives and negatives).
Those numbers should increase dramatically in the coming weeks.
The state is making plans to distribute roughly two million antigen “rapid” tests by the end of the year. The tests, provided by the federal government and produced by Abbott Labs, will be used primarily in schools and nursing homes.
Meanwhile, local officials are pushing mass PCR testing, so-called “assurance testing”, as the best way to prevent COVID-19 outbreaks and to help schools, businesses and government agencies reopen and stay open.
The numbers of tests given will be fairly easy to comprehend, but the reported results will be a bit more complicated.
Positive antigen test results will be reported as “probable” cases of COVID-19. The rapid tests are less accurate than lab-verified PCR tests, and their reliability for those who are asymptomatic is unproven. Results can be reported in about 15 minutes, but any positive results must be confirmed by a regular PCR test.
Positive PCR test results will be reported as “confirmed” cases of COVID-19. Results take about 24 hours, but new lab techniques make the tests easier and less expensive to administer, especially to those who are asymptomatic.
“Antigen is more like scanning the haystack while PCR is like finding a needle in a haystack,” Dr. Lisa Piercey, state health commissioner, explained when the rapid test campaign was announced earlier this month.
The different approaches to mass testing come at a time when COVID-19 cases — and related hospitalizations — are opens in a new windowresurging locally and across the state.
Testing is the only way to know whether a person is potentially contagious and in need of isolation. Nearly 40 percent of people who have COVID-19 do not show symptoms but are contagious.
While the state is pushing the “rapid” tests to find probable cases of COVID-19, local officials are getting behind efforts to rapidly expand “assurance testing” to find confirmed cases.
“Assurance testing” — regular, lab-verified, mass testing of asymptomatic and pre-symptomatic people — is a way to identify and isolate those who are infected with the coronavirus before they even know they have it.
“We’ve made great strides in battling the spread of COVID-19 with hand washing, social distancing and masking,” said Dr. Manoj Jain, a local infectious disease physician who has been advising the city on its COVID-19 response.
“Assurance testing is the next logical step in keeping more people safe.”
On Monday, Mayor Jim Strickland said the city would use CARES funds to pay for lab-verified assurance testing for all students and staff to help Shelby County Schools return to in-person learning in January.
“Assurance testing will reduce the potential of disruption once in-person learning is resumed and position our Shelby County Schools in the same type of program utilized at some of the country’s finest schools and universities,” Strickland wrote in a letter to Dr. Joris Ray, superintendent of Shelby County Schools.
In response, Ray said, “SCS is working with the City of Memphis to provide optional nasal swab testing for students and teachers upon reopening. We aim to learn more about the process and confirm the frequency and equitable access of the City’s testing for all 100,000+ students and 6,000+ teachers and staff. In the meantime, we will continue to share free community testing resources with all staff and families.”
Three of the county’s leading public health experts are encouraging schools to use assurance testing.
Dr. Jon McCullers of the University of Tennessee Health Science Center, and Alisa Haushalter, director of the Shelby County Health Department, and Dr. Jain have agreed to recommend lab-verified assurance testing for local schools, workplaces, and businesses to contain transmission and reduce uncontrolled outbreaks.
“I think it is valuable, both in the sense of providing some early warning of potential cluster outbreaks by identifying asymptomatic persons, and also by providing some reassurance to schools, businesses, and so on, that they are doing OK,” McCullers said.
“You have to be careful, though,” he added, “to recognize that this is screening, and the methods used are not as accurate as one-on-one diagnostic testing. So you can’t let it lead you to be overconfident.”
To prepare for more assurance testing, local labs are producing large quantities of “do-in-yourself” testing kits that dramatically reduce the cost and complexity of PCR analysis.
The kits allow individuals to self-swab at work or at home. The opens in a new windowself-administered nasal swabs only have to be inserted about half an inch inside each nostril for about 15 seconds.
Up to 20 swabs can be placed in one tube on site, then taken to the lab. The collection process can be managed without trained medical professionals or personal protective equipment.
It’s called pod-based testing — the latest development in “pooled testing.”
In pooling, trained lab technicians take samples from five or more people and pool them in a single tube for analysis. Pod testing allows the samples to be collected, or pooled, in one tube on site, then sent to the lab for analysis.
A negative result clears all of samples in the same tube. If a combined tube tests positive, individuals from that pod will be tested again and their samples analyzed separately.
Pooling and pod testing can save time, cost and testing ingredients, if used properly to screen large groups of asymptomatic people.
On Oct. 8, local opens in a new windowPoplar Healthcare became the first medical lab in the nation to receive the FDA’s emergency use authorization for pod testing. American Esoteric Laboratories (AEL) in Memphis also has approval.
“Pod testing gives us an opportunity to get our arms around this pandemic,” Dr. David Smalley, president of AEL’s Mid-South Division, told several dozen members of the Memphis Medical Society on Wednesday.
Smalley and Jim Sweeney, CEO of Poplar Healthcare, said that their two labs could process 50,000 to 60,000 samples every day by using pooling and pod testing. Currently, about 3,000 people a day are being tested in Shelby County.
By testing up to 20 samples at a time, the labs can reduce the cost of each test from about $100 to about $5.
“We see assurance testing as a significant and cost-effective way to protect all of your employees,” Sweeney told the medical society.
The lab directors say they will be able to deliver 50 test kits and process up to a thousand samples a day by mid-November. By mid-December, they will be able to deliver 2,500 kits and process 5,000 samples every day.
St. Jude Children’s Research Hospital has been testing its employees at least once a week for months. The samples are processed in St. Jude’s own labs.
Since August, 14 public charter and private schools in Shelby County have been offering regular testing every week or so to their staff, students and parents.
Jain and his colleagues are talking to other local leaders about joining the mass testing campaign, including the Memphis Chamber and Chairman’s Circle, the Memphis and Shelby County Airport Authority, local hospital chiefs, and suburban mayors and superintendents.
A few months ago, Jain helped to set up an opens in a new windowassurance testing program at Georgia Tech in Atlanta, where his son is enrolled.
About 1,500 of the university’s 20,000 or so students on campus are tested every day. Their saliva samples are pooled and processed at a certified lab.
When the testing program began in mid-August, the school was reporting dozens of positive cases every day. Lately, the school is reporting about 10 positive cases every week.
“We’ve got a long way to go with this pandemic,” Jain said. “We have to continue to push for ways to make schools and workplaces safer to prevent outbreaks and not have to go through another lockdown.”
Organizations interested in assurance-pod testing can contact PoplarHealthcare at 901-473-0684, or AEL at 901-423-8603.
This story first appeared at dailymemphian.com under an exclusive use agreement with The Institute. Photos reprinted with permission of The Daily Memphian.