Medical College of Georgia lab refines COVID-19 testing, secures supplies

Even as it processes around 1,000 tests a day, the big COVID-19 testing facility for the Medical College of Georgia and AU Health System continues to refine techniques and work to secure ever-dwindling supplies.

The Georgia Esoteric and Molecular Lab at MCG and AU Health might have hit on a new method for saliva testing collection that should help correct a major problem, Director Ravindra Kolhe said.

Patients are asked not to eat or drink anything, and not to smoke or chew gum, for at least 60 minutes before showing up for testing, but that doesn’t always happen, he said.

“That has been a national challenge,” Kolhe said, as more labs use saliva-based testing. “If you have food particles, smoking, chewing gum, these end up being a part of the saliva and some of these have PCR inhibitors and this is a PCR-based test. These are very sensitive tests. The tests become invalid.”

The national rate is around 5% invalidated because of contamination, and the MCG lab is under 3%, so they are doing better, he said. But there is also the problem of collecting saliva and not all of the other things that patients will spit into the collection cup, Kolhe said.

“We want to increase the yield of saliva rather than sputum or anything else in the specimen,” he said. “Saliva tends to be tricky with adults because they are trying to push the specimen from the back of the throat.”

MCG hit on using a Saliva Collection Aid, a cover that fits over a collection tube that helps limit what goes into it.

“It’s basically like a straw, rather than an open cup,” Kolhe said.

An initial run at one collection site had zero invalid samples, and it will now be used routinely throughout the system, he said.

While Georgia has seen a slow but steady rise in cases recently, the pandemic has exploded in the Midwest, Upper Midwest and Great Plains areas. That is a concern for everyone, Kolhe said.

“The positivity rate is concerning, rather than the number of positive cases,” he said.

Wyoming, for instance, is seeing an astounding 55.2% positive rate in its daily tests, South Dakota is just below that at 46.2%, and in the South, Alabama leads the way at 28.2%, according to the Coronavirus Resource Center at Johns Hopkins University of Medicine.

Georgia’s rate for PCR tests was 7.2%, and Richmond County’s was 6% for the past two weeks through Wednesday. Columbia County was up to 9.7% and Burke County was the highest in the area at 15.9%, according to data from Georgia Department of Public Health.

Even before that recent national explosion, lab directors had complained about supply chain issues and just finding basics such as plastic-ware to carry out tests, a complaint that has echoed in Augusta.

“We continue to battle the reagent war,” University Hospital CEO Jim Davis told his board about the ongoing fight over chemicals needed to run the tests.

On that front, the GEM Lab has been fortunate, Kolhe said.

“I think we have secured 100,000 tests for the GEM Lab through the (AU Health System) to help the community at least for at least for a couple of months,” he said. “We have secured a pretty decent number of tests for the region.”

The lab also has some flexibility in how it carries out the tests, Kolhe said.

“One of the advantages we have is we have these multiple platforms within the lab, which help us continue to do this testing irrespective of supply-chain constraints,” he said.

One of the challenges they are working on now is adding the capacity to detect influenza A and B strains and the common respiratory syncytial virus that mostly affects children to the same test that looks for the virus that causes COVID-19, known as SARS CoV-2.

“ If you’re negative (for SARS CoV-2), we also want to know the flu status,” Kolhe said.