I noticed two articles today about testing for COVID-19. One talks about two types of tests, and the other spoke about home test kits flying off the shelves.
Types of COVID-19 Tests
https://www.newsmax.com/health/health-news/covid-test-antigen-molecular/2021/08/25/id/1033755/. Many tests can be used to detect coronavirus. According to the FDA, over 100 different tests have been granted Emergency Use Only status.
Antibody tests look for the presence of antibodies that indicate a person has already had the disease (COVID-19 in this case). Diagnostic tests look for the current presence of the SARS-CoV-2 virus. This type of test is usually a molecular or antigen test.
Time for results, cost, and availability are a few things that many of us consider when we need to be tested.
https://www.yalemedicine.org/news/which-covid-test-is-accurate. Most people have had the molecular test – the PCR (polymerase chain reaction) test. This type of test looks for the virus’ RNA. Sensitivity is hyped for this test, but some detractors are the number of false positives and false negatives.
https://www.cdc.gov/csels/dls/locs/2021/07-21-2021-lab-alert-Changes_CDC_RT-PCR_SARS-CoV-2_Testing_1.html is an alert to the world letting us know that the current COVID-19 PCR test is being phased out this year. It will no longer have an EUO status at the beginning of 2022.
https://theconversation.com/why-are-some-covid-test-results-false-positives-and-how-common-are-they-162163 documents the false-positive rate for the PCR test at around 4% – 4,000 people out of 100,000 testing positive when they are not. Is that a big deal? Some think so! Others believe it is acceptable.
A second PCR test administered quickly after the first can confirm if the first test was positive. Statistically, it is unlikely that a 4% error rate would produce two – back-to-back – false positives.
False-positive errors are attributed to laboratory errors, clerical errors, testing wrong samples, cross-contamination, chemical reagents issues, etc.
However, false negatives are a bigger problem. Researchers reviewing data found false negatives between 2%-58%, with about half of the false negatives falling between one and four percent. This means an infected person is found not to have the virus, and that person can infect others because they believe they are virus-free. In addition, false positives can occur when the sensitivity is not perfectly aligned with the virus being tested; and when other viruses (similar coronavirus or having similar RNA features) are found in the test subject.
PCR testing is considered the most accurate and can take a day or longer to get results. Therefore, the FDA recommends multiple tests over several days for absolute verification.
ID NOW – Rapid Molecular COVID-19 Test
https://pubmed.ncbi.nlm.nih.gov/33913533/. This test can be done in doctors’ offices, pharmacies, and minor emergency clinics. It takes about 15 minutes. It is less sensitive than the PCR test and more accurate than the antigen test. https://www.fda.gov/media/136525/download for more information from the FDA on this type of molecular test.
Antigen COVID-19 Test
https://www.mayoclinic.org/diseases-conditions/coronavirus/expert-answers/covid-antibody-tests/faq-20484429. An antigen test detects proteins from the virus. It is usually done after a person has recovered from the COVID-19 virus. It detects if your immune system has responded to the virus and formed antibodies.
The accuracy of the test is affected by the timing – do not get this test when you find out you tested positive from another test. Your immune system may not have adequately responded to the virus. Therefore, there is a probability of false negatives, but that risk is reduced significantly when the test sample is taken correctly.
The Second Article
https://www.newsmax.com/finance/streettalk/cvs-health-abbott-laboratories-binaznow-ellume/2021/08/26/id/1033929/. CVS Health Corporation started limiting the purchase of rapid, over the counter COVID-19 test kits. The demand for home testing has risen with the DELTA Variant. Consumers want the ability to test from home as often as necessary to verify their pandemic status.
When manufacturing responds to the current surge, home test kits at CVS Pharmacies will be more available. Home test kits are rated at 92% accuracy. https://www.nebraskamed.com/COVID/how-accurate-are-at-home-rapid-tests-for-covid-19
The DELTA Variant is more infectious than earlier variants of the coronavirus. Therefore, vaccines do not prevent you from getting the virus. However, they reduce the severity of the virus, which equates to a less frequent need for hospitalization, which lowers the death rate from the pandemic virus.
If there were a $5/home-test kit available that gave results (from home) with 90+% accuracy, then people could buy a dozen or more of them, test themselves often. I believe it would be leaps and bounds towards reducing the spread of coronavirus.
Life Longer & Enjoy Life! – Red O’Laughlin – RedOLaughlin.com