1. What is the difference between diagnostic, screening and surveillance tests?
Diagnostic testing is done on individuals who show signs of symptoms, have been recently exposed or “determine resolution of an infection.” On the other hand, screening is used to identify occurrence at the individual level even if there is no known exposure. Finally, surveillance testing is usually done to monitor a community of population to identify the level of occurrence or outbreak. (Link)
2. What type of test does Syracuse University use to detect COVID-19?
Syracuse University has committed to using a pooled saliva polymerase chain reaction (PCR) screening. This is considered a surveillance test. The protocol was developed and validated by both Upstate Medical University and Quadrant Biosciences. (Link)
*Note: This COVID -19 test has been granted an Emergency Use Authorization for the detection of COVID-19 from the U.S. Food and Drug Administration (FDA); however, it has not been FDA cleared or proved. (Link)
3. What are the advantages of this particular test?
· Polymerase chain reaction (PCR) that identifies viral DNA
· No need for medical personal to collect samples
· Tests can be done outside the testing facility
· Less unpleasant compared to nasopharyngeal swab
4. The test I have done before requires a swab inserted into the nasal cavity; however, this one is just saliva. So what is the difference and does it change accuracy?
The nasal epithelium has been indicated to be the initial infection and an important transmission point of the virus (Link). Therefore, initially the nasopharyngeal swab was a popular testing procedure.
However, as more studies have been done, it was determined that even though the initial infection site is in the nasal epithelium, the virus begins replicating and spreading through the body’s respiratory tract. In a recent study done by Yale University, the saliva tests detected the virus more frequently within the first five days of infection compared to the nasopharyngeal tests. (Link) This indicates that saliva tests are sensitive enough to detect the virus and is comparable to that of nasopharyngeal tests.
Science talk if you’re interested: Upon entry, the spike proteins on the coronavirus interact and bind to the receptor of a protein (ACE2) predominantly present in nasal epithelial cells. It has been reported that this interaction is the determinant of the SARS-CoV-2 replication rate. During testing, samples were obtained deep in the nose because the expression of ACE2 was higher. However, studies have also indicated that high ACE2 expression is also present in the epithelial cells of the oral mucosa and the base of the tongue. Therefore, saliva test can be used which is a minimally invasive, reliable and reproducible test. On May 8, 2020, the FDA approved salivary test to detect COVID. (Link)
5. What is the process for testing from the day I come in for testing to the end results?
a. Student Involvement (Link)
i. Approach the testing site with your ID and stand six feet apart from everyone
ii. You’ll be asked several questions (Do you have any COVID-19 symptoms? Were you exposed to someone with COVID-19? Did you have any food or drink within the last 30 mins?)
iii. Students will be handed a package containing a tube with a swab. Carefully, expose the swab (the sponge part) and collect saliva from your mouth for 30secs.
iv. Then place the sponge end of the swab into collection tube and screw it tightly
v. Once cap is secured, shake it vigorously for 15sec
vi. Collection tube is then collected by the attendant for scanning and further processing. This involves scanning your ID card with the barcode of the collection tube bag.
b. Lab Involvement (Link)
i. The labeled bag is open to remove the pooling tube.
ii.Collection tubes from patients are then emptied into the pooling tube.
iii. At each step, the barcode is verified with the collection tube, the pooled tube and the bag the collection tube came in.
iv. This sample is then taken to a lab for polymerase chain reaction (PCR) testing?
c. School Involvement
i. Within a few days the school will contact you with results.
6. How many samples are included in one pooled testing?
Upstate Medical University allows about 10-25 people to be screened in one test. (Link)