Serkan Alan / DUVAR
The tests that identify coronavirus can be grouped into two large categories, said Prof. Alpay Azap, member of the parliamentary scientific board and chair of the Turkish Society of Clinical Microbiology and Infectious Diseases (KLIMIK).
The most often used Polmyerase Chain Reaction (PCR) tests reveal the RNA of the virus, Azap said, adding that it takes about three hours to give results.
Often dubbed “test kits,” the faster tests check for antibodies in a potential patient’s blood or for antigens in a person’s airways, Azap said, adding that the latter isn’t as reliable, which is why the antibody test is often preferred.
“The antibody test is more reliable but it takes five to six days after infection for the antibodies to appear in the patient’s bloodstream and for them to test positive. So in short, the PCR tests are the best.”
Controversy around “test kits”
On the other hand, these testing kits simply work as a pre-diagnosis and positive-testing patients need to be further tested, said Dr. Cavit Işık Yavuz, member of the Turkish Medical Association’s Public Health Branch.
“These kits yield results in 15 minutes. It does a pre-diagnosis of positive or negative. You’ll get those results, and test the positive patients with the diagnostic PCR test,” Yavuz said.
However, “test kits” or the “pre-diagnostic” tests aren’t useless at all, Yavuz notes, as they might give healthcare workers a chance at using the PCR tests more efficiently.
“They help in that we know who to test with the PCR first, it’ll be the patients who tested positive on the test kit. We will have de-prioritized those who tested negative,” Yavuz said.
Adding that the faster “test kits” might display false positives or false negatives, Yavuz notes that they are still useful to help prioritize patients for PCR testing.