Make Screening Tests More Available, Not Less
By Sheetal Khedkar Rao, MD
SARS-CoV-2 screening tests can help stem the tide of new infections. Unfortunately, the Centers for Disease Control (CDC) recently stated that all SARS-CoV-2 screening tests must receive Emergency Use Authorization (EUA) from the FDA and fulfill Clinical Laboratory Improvement Amendments (CLIA) certification. Until December 3, screening tests did not need to meet these requirements. These new regulations introduce unnecessary hurdles into the process of SARS-CoV-2 screening and will likely slow down efforts to identify people with asymptomatic infections. Screening can help people stay safe and return to some semblance of normalcy as we await vaccine rollout. As case counts continue to skyrocket, now is the time to expand screening, not impede it, as the CDC has done.
Screening is just one of the public health strategies of testing. Screening tests are performed in asymptomatic individuals who lack any known or suspected exposures. Each individual is linked to their data, so someone with a positive test still needs a diagnostic test for confirmation, but would be asked to quarantine until it resulted. In this way, screening helps reduce viral exposure of SARS-CoV-2 to other individuals in the group by isolating the initially positive individual until confirmatory testing is completed. Screening could be used weekly, for example, to test all amenable students and staff in a school building, in order to identify asymptomatic positives. Such a strategy, applied widely, could help students in many parts of our country return to public school.
Though not the panacea that we all dream of, screening is an added layer of protection against the storm of uncertainty that is SARS-CoV-2. Michael Mina, a Harvard University epidemiologist has been advocating for a colossal expansion of screening tests for months. Why? Because people with higher loads of virus who are pre-symptomatic are more likely to transmit SARS-CoV-2 to others. Yes, masks and social distance are crucial, proven strategies (testing or not), but we see all too many people ignoring these measures--hence our current predicament.
FDA approval and CLIA certification add time and expense to screening costs, and lack proven benefit. If we were talking about a SARS-CoV-2 vaccine or a new treatment, then yes, FDA approval is absolutely crucial. Screening tests, on the other hand, are not ingested. They are meant to be confirmed with diagnostic testing. They are meant to be repeated for increased sensitivity. They should be reasonably accurate, of course; but not at the expense of the weeks and months of time it takes to get FDA EUA! Some schools and universities have already demonstrated the value of screening tests that don’t have FDA EUA. The University of Illinois at Urbana-Champaign (UIUC) started screening all of their undergraduates on August 15th, 2020, using their Shield program. On Aug. 31, after a spike in cases with 230 new cases in one day, screening tests helped to identify multiple super-spreader events. UIUC has since expanded their screening tests to multiple campuses across the state despite awaiting FDA EUA for months. In LaGrange, Illinois, Dr. Ed Campbell adapted the RT-Lamp screening test at his son’s elementary school district. His program has been successful enough to not only keep his son's school open safely, but help several other school districts do the same without FDA EUA or CLIA certification. The ingenuity and perseverance demonstrated by UIUC and Dr. Campbell should be encouraged and supported by the CDC, but instead they’ve set forth new requirements effectively hobbling the efforts of schools to adopt screening. The media brims with articles stressing that students benefit from being in school, so why further challenge schools that desire an additional layer of safety?
As the pandemic progresses and the second wave brings worsening daily death tolls, we need to use all the effective tools we can. The likely imminent rollout of vaccines in the US will help protect healthcare workers and the most vulnerable Americans. Unfortunately, it will take months to attain the 75-85% vaccination rate that Dr. Fauci deems necessary for herd immunity. Imagine if, in the meantime, we have access to screening testing on a mass scale. When added to masking and distancing, we can more safely do some of the things that make our lives feel normal. By adding on FDA and CLIA requirements, which are of questionable utility in this particular situation, the CDC is effectively putting in roadblocks, when they should be paving a yellow brick road. With cases exponentially increasing and potential herd immunity months away, this is the wrong time to make screening more difficult.