With successes in countries like South Korea, Taiwan, and Germany, testing and contact tracing have proven to be the crucial weapons for the survivability of nations under economic duress during this war against an invisible enemy.
Some countries have seen crucial failure in testing roll-outs. In February, the United States rejected using the WHO approved and validated test kits early in the process. It sent out its CDC (Centers For Disease Control) test kits that were faulty and produced inconclusive results. Samples had to be sent to its central laboratory in Atlanta. Not only were there a shortage of test kits available, flawed kits and travel time obliterated America’s ample lead time against the virus.
With federal response and coordination in shambles, states were forced to search for their own resources for testing. Losing pivotal time, the FDA eventually loosened its restrictions in March.
With little assistance from the federal government, states had to individually scramble for supplies and test kits from other countries and providers.
On April 16th, an NBC News article called out at least two cities and two states that are currently using unapproved COVID-19 antibody tests including Denver and Los Angeles and urgent care centers in Maryland and North Carolina. The concern was that these test kits were not approved by China’s Center for Medical Device Evaluation (a branch of China’s FDA-type agency) or by the U.S. FDA.
Two U.S. companies Premier Biotech of Minneapolis and Aytu Bioscience of Colorado have been distributing tests after the FDA relaxed its guidelines in March. Tests made by two Chinese manufacturers Hangzhou Biotest Biotech Co. (provides to Premier Biotech) and Zhejiang Orient Gene Biotech (supplies Aytu Bioscience) are not approved on the list and are being sold in the US. The article suggested that the Aytu kits had “considerable number of false positives”. Nonetheless, this may be anecdotal because the LADPH partnered up with University of Southern California and an independent study published in Infection Ecology & Epidemiology supported its reliability.
The fact remains that none of the current testing methods have undergone the rigorous examination for FDA approval.
Why aren’t any these tests FDA approved?
At the moment, the U.S. does not have any “FDA-approved” diagnostic methodologies. The severity of inadequate testing in the Unites States forced the agency to loosen its restrictions. As of this article, the FDA website currently states “There are no FDA-approved diagnostics for COVID-19.” Test kits are authorized under FDA’s Emergency Use Authorization (EUA).
In the war against COVID-19, testing is the number one weapon. But like all arsenals, one interminable fact remains: NOT ALL TEST KITS ARE MADE EQUAL.
The main methodologies for the determination COVID-19 infection are as follows:
1) Real Time Reverse Transcriptase Polymerase Chain Reaction (RT-PCR)
What is RT PCR?
Once a nasopharyngreal swab is inserted, it’s twisted enough times in hopes of picking up a piece of the RNA VIRUS that is COVID-19. Since RNA is complementary to DNA, a DNA complementary is created and added to an enzyme called reverse transcriptase with complementary primers in the mix.
A single copy of DNA is multiplied through processes called denaturation, annealing, and extension. Each cycle to double a strand of DNA lasts ten minutes and the process is repeated to produce roughly one trillion copies.
Getting a good sample is CRUCIAL. If no virus gets on the swab, PCR will not be able to detect it.
How long does this test take?
Varies from hours to days.
One step requires less time than two step PCR method but each process is time consuming.
Is one RT-PCR Test more accurate than another?
This test measures the amount of specific RNA using fluorescence. RT-PCR products are put through gel electrophoresis. Two step RT-PCR is more accurate than one step RT-PCR with a longer turn around time.
How reliable is this test?
The test is a real-time reverse transcription–polymerase chain reaction (rRT-PCR) assay that can be used to diagnose the virus in respiratory and serum samples from clinical specimens.
The original CDC rRT-PCR test was recalled due to ineffective reagents. The CDC has since developed an updated protocol that excludes the need for third component that was causing the problem.
RT-PCR is currently considered the “gold standard” for tests.
On April 13, 2020, the FDA granted EUA for a saliva-based COVID-19 test, which can be used to test patients’ self-collected saliva rather than swabs collected by healthcare personnel, potentially limiting exposure and increasing the capacity for testing.
Self-collected swabs new increase false negatives due to improper collection.
2) Antibody testing