AUSTIN (KXAN) — Austin Public Health is looking into the possibility of using a faster type of COVID-19 test than it’s currently administering on patients, Dr. Mark Escott said in a briefing with Travis County Commissioners.
Currently, the health department uses PCR tests, which are swabs that are sent to labs to detect the virus. But Escott says as the use of antigen tests is growing, the county is looking at those as an option.
Antigen tests produce results more rapidly than PCR tests. Escott says antigen tests can yield a positive or negative test result as quickly as 15 minutes.
“If we have a test that we can reliably use that we can, you know, provide an answer to someone before they leave our site, we can get a whole lot better control over this for future outbreaks than sending off tests that are going to take three or four, 10 days,” Escott told county commissioners.
However, Escott admits antigen tests don’t have as high of an accuracy as traditional PCR tests.
“It’s not quite as accurate as the regular PCR testing that we send off to labs, but it’s probably good enough,” he said.
He added that the antigen tests “may not be detecting cases where disease transmission is not possible, because the viral load is so low.”
“It’d be nice to know about those cases, but it’s not really essential for public health to know about cases that can’t transmit,” Escott explained.
Tarrytown Pharmacy began using an FDA Emergency Use Authorized antigen test administered through nasal swab about a week and a half ago.
“It’s been insanely popular just because of the lack of testing available in Austin and the importance of being able to get quick and rapid results,” said pharmacist James Cong.
Cong says Tarrytown Pharmacy currently has the capacity to administer about 50 of the tests per day and those slots have been completely booked almost every day. The pharmacy is working to double its capacity for testing, soon.
Cong says with the machine the pharmacy uses to test samples on-site, results are often ready in as little as 20 to 30 minutes. The pharmacy can then call the patient, tell him or her how to proceed and offer a consultation with a pharmacist, if needed.
“So the positives, in my opinion, greatly outweigh the negatives in being able to get a result back and in the chance that you are positive, you know not to interact with others, quarantine yourself for 14 days, and then seek follow up,” Cong said.
Cong says antigen tests can yield false positives anywhere from 10 to 20% of the time. However, he says, those that come back positive can generally be trusted to be a truly positive result.
Cong says because of the higher rate of false positives with antigen testing, he still recommends that anyone with symptoms who tests positive quarantine and possibly follow up with a traditional PCR test.
He says many of those who have tested positive using the antigen testing at Tarrytown Pharmacy, however, have been asymptomatic.
“Those are people who, if they had to wait six to 10 days for a test result to come back, they may be more inclined to interact with family members and friends, go to work, just interact with the general public,” Cong said. “So, the positives, in my opinion, greatly outweigh the negatives.”