COVID-19 test an uncomfortable but life-saving measure
Being tested for the COVID-19 coronavirus can be a brief, uncomfortable experience, but the results could determine whether you are in the clear and healthy or need medical support immediately. So how does a coronavirus test work? Residents might have that question since Moose Jaw is one of 40 testing centres that collect samples and ships them to provincial labs. The Moose Jaw Express turned to Dr. Joseph Blondeau, the provincial lead of clinical microbiology and head of clinical microbiology at Royal University Hospital in Saskatoon, for an explanation.
A specimen is taken from a patient’s sinus cavity through the use of a nasopharyngeal swab, which is “a long swabby thing they stick up your nose,” he laughed. “It’s a flexible swab that has some absorbent material on the end of it … .”
The swab goes up and is twisted to collect “some good material,” Blondeau said. While the test doesn’t hurt, it can be uncomfortable and cause patients’ eyes to water. Once removed, the swab is put into a tube of media to protect it during transportation to the laboratory for testing. There are two main testing laboratories in Saskatchewan: the Roy Romanow Provincial Laboratory in Regina and the microbiology laboratory at Royal University Hospital in Saskatoon.
Once the specimen is at the lab, researchers take the sample and extract the nucleic acid. A test is conducted to see if specific components of the COVID-19 coronavirus are on the specimen. The test checks for two genes within the virus. Once that is completed, a process called amplification occurs to see whether the specimen is positive or negative for the genetic markers for COVID-19.
The test can occur quickly depending upon when the tube is delivered. If the specimen is delivered in the morning, a result could be produced by noon, said Blondeau.
“We have a province which is a vast landmass, where patients live in almost every corner of it. … What we say is our turnaround time is less than 24 hours, but the reality is, once you take transportation out of the equation, once the specimen is in the laboratory, a result could be available in as little as four hours,” he added. The tests are completed at the two licensed labs in the province to ensure accuracy. Every test is controlled, which means there are known positive or negative samples on hand. For the test to be valid, the internal controls have to give the expected response. Those controls guarantee that the expected reactions have occurred. These are quality control factors that guarantee the accuracy of the tests.
If researchers amplify a product and don’t see an increase in the number of copies of that product, the assumption is those targets are not there and researchers can infer COVID-19 is not present, Blondeau explained. Conversely, if the product is amplified and extra copies are produced, then the sample is positive with the virus. Besides the two main testing labs in Saskatchewan, there are point-of-care testing kits that have been delivered to communities for quick results. These kits can perform a low volume of testing and conduct tests if the situation is urgent. The results are accurate enough to determine the patient’s health.
For about 80 per cent of the population, most people will come down with a hardly noticeable symptomatic infection, said Blondeau. For the other 20 per cent, they will require hospitalization and admission to intensive care and would need to be put on a ventilator.
“Because of the global spread of this virus and the number of deaths worldwide, this is not a virus to be taken lightly. This is a serious problem,” he added. “The steps we’re taking to deal with this virus and limit its spread are so vitally important it’s beyond statement.”