Clinical Testing For Covid-19

Ward, Stephanie; Lindsley, Andrew; Courter, Josh; Assa’ad, Amal

Abstract As the novel coronavirus SARS-CoV-2 caused COVID-19 cases in the United States the initial test was developed and performed at the Center for Disease Control (CDC). As the number of cases increased the demand for tests multiplied, leading the CDC to utilize the Emergency Utilization Authorization to allow clinical and commercial laboratories to develop tests to detect the presence of the virus. Many nucleic acid tests based on reverse transcriptase-polymerase chain reaction (RT-PCR) were developed, each with different techniques, specifications and turnaround time. As the illnesses turned into a pandemic, testing became more crucial. The test supply became inadequate to meet the need that it had to be prioritized according to guidance. For surveillance, the need for serologic tests emerged. Here we review the timeline of test development, the turn-around times, the various approved tests and compare them as regards the genes they detect. We concentrate on the point-of-care tests and discuss the basis for new serologic tests. We discuss the testing guidance for prioritization and their application in a hospital setting. As SARS-CoV-2 virus arrived in the USA causing the COVID-19 illness, one of the most talked about issues in the management of the disease and the resulting pandemic has been clinical testing. A unique situation arose of a communicable and highly contagious disease necessitating the rapid diagnosis of patients and the identification of non-symptomatic infected persons. Unfortunately, the USA did not have a Food and Drug Administration (FDA) approved laboratory test for the illness. The FDA ultimately utilized its Emergency Use Authorizations (EUA) on February 4, 2020 to allow for more rapid and widespread development and implementation of in-vitro testing.1 Indeed, companies and organizations utilized the EUA to file applications for new tests based on different methodologies, amounting to 48 applications in the span of 3 months from the beginning of February to the end of April 2020. In addition, multiple other tests were put in place under a separate authorization by a Presidential memorandum in early March allowing laboratories that carry Clinical Laboratory Improvement Amendment (CLIA) certification to put tests in place without an EUA from the FDA. This created an unprecedented situation where the medical community and the public may not be familiar with the various new tests for COVID-19 that are offered to patients and hospitals. The purpose of this review is to provide information, up-to-date as of the date of submission of the manuscript to the journal, on the various tests that have been developed, their scientific basis and their interpretation. We give a real-world example demonstrating the time lag in the return of test results and review testing prioritization guidance since the supply of tests remains below the perceived need.