When I get asked the same questions about anything I realize that it requires a blog to write. Many of my patients wonder what is PCR and what is Rapid test for COVID-19 viral disease.
Here is the answer in a nutshell. PCR stands for polymerase chain reaction. It is the name of the technique the laboratories use to detect genetic material of the viral COVID-19 molecule. The test is also called molecular test. RT-PCR means real-time - polymerase chain reaction. The accuracy of the test is about 95% sensitivity and 98% specificity.
On the other hand, rapid test is an antigen test. It is not a molecular test and it does not detect the genetics of the virus. It is an antigen test that detects specific proteins from the virus and has less accuracy. There are multiple rapid tests on the market today. Be advised the sensitivity and specificity of the rapid tests are not widely published. The sensitivity and specificity vary and depend of the manufacture. It can be from 56% to 88% and the specificity is around 98%. I want to say that out of the many legit studies that I went through about 30% of the rapid test results are false.
Which test for COVID-19 would I advise for my patients?
If you are experiencing signs and symptoms of the disease, I would never advise you to do rapid test. You should do either both or PCR only. You and people around you want to know what are the chances you have COVID-19 disease, therefore, if you have a choice to get higher accuracy test, why do rapid only?
If you are not experiencing any symptoms and required to get tested for your travel, job clearance, or visitation of your family, and you do not suspect any exposure in a specific situation - rapid can be an option. However, it can never be treated as a pass to not use simple precautions as social distancing, wearing masks, and hand hygiene.
Please know - neither PCR or Rapid test rules out COVID-19 disease, particularly, if you have symptoms of the disease.
What was your experience?