In the wake of COVID-19, testing for the virus has become the norm in all of our lives. Testing is required for many things these days, most of all to travel. Since the virus symptoms are often quite similar to that of the flu, testing has become the go to in order to find out whether we have COVID or it’s something else. The problem is there are so many types of tests and names thrown around, how do we know what we should be getting and why? We’re going to dive into the main types of testing, so that you have a better understanding of what it is you should be getting and why. This will come in handy especially when you’re trying to travel through countries all having different requirements for testing.
The first is what you probably know as a PCR test. The PCR test is a type of molecular test which is also called RT-PCR or RNA testing, and what it does is detect specific genetic material or pieces of the actual COVID-19 virus. It uses a special technique called polymerase chain reaction to detect these pieces and is why it is called PCR. This is considered the gold standard for all testing because it is the most accurate. We won’t deep dive into the accuracy numbers because there is so much varying information, but generally an RT-PCR test has accuracy in the very high 90’s up to the 99.9 percentile. A nasal or throat swab is taken which is then put through special equipment to detect the virus for an active infection. This usually must be sent to a lab with this equipment which is why it takes a few days to receive results back.
The second type of primary testing is most commonly called Antigen tests, but also known as rapid tests, rapid antigen tests and lateral flow tests (for our UK neighbours!). Antigen tests look for pieces of proteins that make up the COVID-19 virus to determine an active infection or not. These proteins are known as antigens, hence the name. Seems logical, but most people don’t actual know why it is called an antigen test! They are also called rapid tests because you can get results from a test as quickly as a few minutes. A similar process for a throat or nasal swab is undertaken, but rather than being sent into special equipment, it can simply be put into a special solution. This solution is then poured over an indicator which shows a line to indicate a negative or positive result. If this sounds like a pregnancy test, it’s because it is and has a very similar indication process. While antigen tests are quite accurate, they are not as accurate as RT-PCR tests, with numbers generally in the low to high 90 percentages. However, the ease of use, quickness of results and much cheaper cost mean they are the better option in many cases.