I tested positive with covidSHIELD and negative with nasal PCR or other test. Which result is correct?
Not all PCR tests are the same. They run on different PCR instruments, use different reagents, look for different genes, etc. etc. For example, the covidSHIELD saliva test is more reliable overall compared to self-collected nasal specimens. Nasal PCR has a higher false/negative rate and lower sensitivity in most studies. The covidSHIELD test is also much more accurate than antigen (sometimes referred to as "rapid") tests.
Proving a specimen is negative is more difficult than proving it is positive. A positive covidSHIELD test means that, at a minimum, two genes unique to SARS-CoV-2 were detected in the specimen. A negative test is technically “not detected” which means there could be SARS-CoV-2 there but we couldn’t find it. I always give this silly analogy: If I looked out my window and saw a dinosaur in my yard, I would be positive there is a dinosaur in my yard. If I looked out my window and didn’t see a dinosaur in my yard, that doesn’t mean there isn’t one there. It might just be somewhere I can’t see through the window. A specimen that tests positive for SARS-CoV-2 with covidSHIELD had the virus in the sample that was tested. We saw the dinosaur.
In short, a positive result from covidSHIELD should be treated like a positive. Your healthcare provider or local health department can help you to determine what that means for you.
Does SHIELD Illinois offer Binax (antigen) testing?
The short answer is "yes." The long answer is SHIELD Illinois only provides operational support for BINAX testing for K-12 public schools which are already participating in the SHIELD Illinois covidSHIELD saliva testing program. Overview SHIELD ...
Could something I ate have caused a false positive?
No. SHIELD Illinois encourages everyone to refrain from eating or drinking for 60 minutes before the test to prevent the specimen from being rejected by the lab or producing a result of INVALID. Eating or drinking before the test would not cause an ...
How reliable are covidSHIELD test results?
In a recent study, the saliva test was shown to have a specificity of 98.9% and a sensitivity of 95.8%. The FDA-authorized covidSHIELD test targets three highly conserved regions of the viral genome for detection. High specificity offered by ...
I don't have any symptoms. Is this a false positive?
It is extremely unlikely for the covidSHIELD test to produce a false positive result. In a recent study, the saliva test was shown to have a specificity of 98.9% and a sensitivity of 95.8% which makes it one of the most accurate tests in the world. ...
What is covidSHIELD’s false positive rate? I heard the test is no more accurate than a coin flip, or 50/50. Is that true?
The answer to that is, unequivocally, "no." And it is wrong by a long shot. Let me explain: In a perfect world, we would know the exact number of infected people, which would be the starting point in making such a calculation. Without knowing that ...