Which tests work best? Doctors address COVID-19 testing questions amid surging omicron cases in Bexar County

Health care professionals say all tests are effective, but it depends on how and when they’re administered

SAN ANTONIO – Antibody or PCR? Rapid or at-home? There are options when it comes to testing for COVID-19 amid surging cases in Bexar County.

Dr. Fred Campbell, an associate professor and internal medicine physician at UT Health San Antonio, said people can put their faith in one above the rest.

“PCR test is the gold standard,” Campbell said.

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Campbell said, according to data from The Medical Letter, a periodical from Harvard and Yale, at-home tests and rapid tests are still sensitive enough to detect all COVID-19 variants.

“The reliability is very high, at least 85 to 90%. So I’m very confident that these screening tests will be reliable,” Campbell said.

Infectious disease epidemiologist Cherise Rohr Allegrini, Ph.D., MPH, agrees those tests are sensitive enough to detect the virus, but they need to be administered correctly and at the right time.

“Which means you really get that Q-tip up in your nose, rub it around at least five times on each side, and you do it properly. There’s a good chance it’s going to detect if you’re infectious at that moment,” Rohr Allegrini said.

Rohr Allegrini mentioned the timing because if you test too early, there isn’t enough virus for the test to pick up.

KSAT Q&A: San Antonio epidemiologist discusses COVID-19 omicron variant trends, testing differences

The Centers for Disease Control and Prevention recommends testing five to seven days after possible exposure or as soon as symptoms start.

As far as rumors on social media about swabbing your throat rather than your nose to detect omicron, Campbell says that’s not true.

“(Use) a nasal swab to diagnose the omicron variant as it does live in the upper respiratory tract,” Campbell said.

He said there’s always room for error with these tests -- a false negative. So if you’re feeling ill, stay home.

About the Authors

Leigh Waldman is an investigative reporter at KSAT 12. She joined the station in 2021. Leigh comes to San Antonio from the Midwest after spending time at a station in Omaha, NE. After two winters there, she knew it was time to come home to Texas. When Leigh is not at work, she enjoys eating, playing with her dogs and spending time with family.

Gavin Nesbitt is a photojournalist and video editor who joined KSAT in September 2021. He has traveled across the great state of Texas to film, conduct interviews and edit many major news stories, including the White Settlement church shooting, Hurricane Hanna, 2020 presidential campaigns, Texas border coverage and the Spurs.

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