Dr. Leslie Cordes is the senior medical consultant at Latin School of Chicago. She is also a pediatrician and has been a physician for 36 years. She has a master's in public health with a focus in epidemiology.
What is the SARS-CoV-2 saliva screening and what does it measure?
Well, the process we're offering at Latin uses saliva samples and in an assay method, a method of detecting that's called RT-LAMP. In long terms it's called reverse transcription loop mediated isothermal amplification. What that does is it uses amplification methods on the saliva sample to detect SARS-CoV-2 RNA. And that's the virus that causes the disease that we know as COVID-19. And while this method is not as sensitive as PCR tests that you may have heard of and detecting that viral RNA, the cost and the quick turnaround time of this particular test, make it a very good screening tool. Both RT-LAMP that we're going to be using and PCR are categorized as a nucleic acid amplification test, which detects the genetic material or the RNA of the virus. And that's in contrast to the antigen tests that you also may have heard of, which are designed to detect certain viral proteins.
How will this saliva screener make our school safer? And can we relax other measures such as the mask and distancing and such?
Well, the saliva-based screening adds another layer to Latin's mitigation strategy. And it's The saliva-based screening adds another layer to Latin's mitigation strategy.
Dr. Leslie Cordes very, very important that our community recognize that it doesn't in any way take away the measures that have been in place since the start of school, including the proper and consistent masking, distancing, hand washing, and the many measures that were clearly outlined in the return to plan. But by instituting that screening protocol, we aim to identify and isolate the asymptomatic and presymptomatic cases of COVID-19 thus reducing the risk of transmission. So these are those people who may never have symptoms of COVID-19 yet are able to spread it, or those who we are catching early, who will go on to develop symptoms, but again could be transmitting. So we are, we are working to remove these individuals from the community as a way to reduce the risk of transmission.
Who is it that gave us the idea about starting this test?
This test was developed for use in the school systems by Dr. Ed Campbell, who was professor of immunology and microbiology at Loyola University in Maywood. And he is a member of the school board of his own children's school out in LaGrange, Illinois. And as we were working through this pandemic, he started to realize that some of the techniques that he is familiar with in the laboratory and that some of his colleagues at University of Wisconsin, Madison and University of Colorado, Boulder, were working on, could be very helpful in establishing a screening program that could be used in schools. With the goal of having something that is cost effective for the school system and had a very quick turnaround time, both of which are hallmarks of a good screening test. So he and his lab and his other colleagues collaborated to create this, a screening test and began implementing it at his own kid's school at the start of the school year.
If we look at the other schools that are using this test, what kind of results do we see?
Well, we do see that it has been effective at picking up some asymptomatic cases. Thus far, the reported results, looking at the schools that have been using it, are picking up about half a percent of those who were screened. So those are people that were coming into school feeling well with no signs at all of COVID-19 who are then having tests that have been detected and then subsequently confirmed by PCR. So again, if we're looking to see what numbers we're reaching, we're looking at probably in the neighborhood of about a half of a percent for those screened.
What will be the procedure if I have already tested positive for COVID in the past?
If someone is tested positive for COVID-19 within the past 90 days or three months, we will not be asking that individual to submit a saliva sample.
Does this saliva screener replace a PCR test?
The answer to that is a very definitive, no, it does not. This is a screening test. It is not diagnostic and it is only for the purpose of alerting us. So we are going to ask all those that they then receive a diagnostic PCR test. We're also going to ask those individuals to isolate, and we will perform contact tracing as if this were an identified case. We're again going to then follow up with the diagnostic PCR test.We at Latin are really working very hard to reduce the risk of viral transmission in the school and establish our school as a safe learning environment for all.
Dr. Leslie Cordes
What resources can you look into if you're interested in more information on this saliva testing or testing in general?
I would recommend folks go to the CDC website. The work on testing and testing strategies and all the various options is evolving so very rapidly. The Centers for Disease Control and Prevention regularly updates its website. So go to CDC.gov to search for screening strategies, various types of tests and for the most updated information available.
Why does all this matter?
We at Latin are really working very hard to reduce the risk of viral transmission in the school and establish our school as a safe learning environment for all.