Health experts discuss testing reliability and virus mutation

New research says that COVID-19 has mutated to become more infectious. With the continued surge in cases, Houston health leaders addressed which type of test will provide the most accurate results.

Health officials say the mutated, more infectious virus now exists in nearly 80% of the cases in Houston.

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Dr. Joseph Petrosino is the Chairman of the Department of Molecular Biology and Microbiology with Baylor College of Medicine.

"The mutation that we're seeing in Houston is prevalent in about 70 to 80% of the cases that we've looked at that includes other cases that have been published from the hospitals," Dr. Petrosino said. 

Citing new research from a Scripps study published last month, Dr. Petrosino said the Coronavirus has now mutated to spread more easily since the early stages of the pandemic.

Although more infectious, researchers say the virus has not mutated to become more lethal.

"From and looking at the clinical data. People do not get sicker than not die at any greater frequency. It is imperative to practice social distancing and wear masks," Dr. Petrosino said. 

"Simultaneously, there is a document with over 200 signatures from scientists around the world going around the WHO asking them to reclassify the virus from being droplet transmission to airborne transmission. If that's true, that would be a game-changer for us," said Dr. David Persse, Houston's Health Authority. 

DETAILS: Nearly 240 scientists urge WHO to acknowledge coronavirus can spread in air

Dr. Persse said if the virus mutates in transmissibility to that extent would significantly change the way local leaders make decisions about “super spreader” events.

Dr. Persse encourages folks who want or need to get tested, to rely on the traditional nasal swab for the most accurate results calling it the “gold standard for testing”.

"The nasal swab tests that go off to a lab that takes a day or two, sometimes five to get the results back are highly accurate. Those are the most accurate tests. The next most accurate tests are the ones that are brand new and it’s just hitting the market, that’s the one with the saliva test. It’s an antigen test," Dr. Persse said. 
Dr. Persse said the least reliable are the rapid tests.

"I don’t consider those to be terribly reliable. There is one test that is the Abbott ID now test – where you can get an answer back in as little as 15, maybe 30 minutes. If you get a positive result, that’s pretty reliable. Unfortunately, they miss a lot. So negatives don’t really help you out at all," said Dr. Persse. 

Dr. Petrosino said rapid tests can provide false negatives up to 20% of the time.