Testing for COVID-19 is an important step in tracking cases and contagion mapping. It also tells us who needs treatment and isolation. At some point, COVID-19 testing will be needed in order for us to get back to “business as usual” as a country (and as a planet!). That being said, there are many different types of tests out there, not all using the same specimen type, not all taking the same amount of time for results; it’s a lot to wade through and there is too much misinformation out there. I am going to (hopefully) help you make some sense of this by breaking down all of the currently available testing methods. Please keep in mind, this information is evolving rapidly (I had to make changes over the course of the few days this was written!), but this is the best information available at the time of publishing.
Laboratory Nasal Swab (Nasopharyngeal Culture) Test
This is a molecular test in that it tests for the RNA/DNA (genetic building blocks) of the SARS-CoV-2 (COVID-19) live virus. Since this detects the live virus, a positive test indicates that the body is currently infected with the virus. It’s doesn’t determine when in the timeline the infection is (onset, peak, or outset). Also, important to note: if there is live virus in your body, then you are contagious. The specimen for this test is mucous collected (most-commonly) from the posterior nasopharynx (the upper part of the nasal passage), and it collected by taking a cotton swab and inserting it to the back of the nasal passage. The specimen is processed at the lab with a process called RT-PCR (real-time polymerase chain reaction) which – in very basic terms – is a DNA replication/splicing to check compatibility. If the DNA is able to replicate, then it proves the presence of this particular coronavirus. While we have seen instances of false negative results, they are almost entirely due to poor or erroneous collection techniques. Aside from that, this is an extremely accurate way to detect it. Lastly, because this is a lab test, the results are not immediately available and can take days (or more, depending on the lab).
Instant Nasal Swab (Nasopharyngeal Culture) Test – “Abbott ID Now”
This one is relatively new, having only received its FDA EUA (emergency use authorization) on March 27th of this year. Like the laboratory test above, it is a molecular test. The specimen is also mucous, but instructions indicate it be collected from the nose, throat, nasopharynx, or oropharynx (back of the throat). The big difference between this and the lab test is that this is a standalone testing unit than can provide a near-instant result (5-13 minutes). The accuracy, while not quite as good as the lab test above, is still an impressive 95% per the manufacturer’s documentation. There are another 2 or 3 devices that are similar to this, and either FDA cleared (or close) that will have results within an hour; I focused on the Abbott device because many of you probably saw it on the news where President Trump had one out on the table during a press conference.
Instant Serology Immunoassay
Lastly, we have the newest test to be made available – an instant device that works much like the old pipette (eyedropper) style drug and pregnancy tests. Also, like most drug tests devices, the result is available within 15 minutes! It is a serology test, meaning the specimen needed is blood (whole blood, serum, or plasma). This test is different than the others above in that it is testing for the antibody that your body creates when exposed to the virus. This means it will detect whether you currently have or have had the virus; in other words, you may have already cleared the virus from your body and still trigger a positive on this test. As it is a screen, it is less accurate than the molecular tests, with most on the market between 82%-90% accuracy. There are more than 40 manufacturers who have either filed for an EUA (or have notified the FDA of their intent to do so), but as of this writing, only one has approved. There is some confusion as to the collection method for the blood specimen: it is being widely described as a finger stick test – finger stick being a minimally invasive method of pricking the fingertip to draw a bead of blood (diabetics do many times this daily). However, in an effort to discourage home use, any serology test that has been FDA cleared will clearly state that finger stick is not an acceptable method of collection. Unfortunately, there are no COVID-19 tests that are currently available for home use. Lastly, we do have these tests available, so please reach out to your consultant for more information or click here to fill out an order request form.
I hope I have shed some light on the available tests that are out there. Again, since this is changing so fast, do not hesitate to check in with us if you need to take any steps based on the information here – just to be sure. Our next post will be about some tips and tricks on how to keep a clean and safe working environment as we start trying to get back to work or as some of you continue to do so already. If you have any tips or information on how you are performing testing in a world where social distancing is becoming the new norm please comment and share. The best thing we can do right now is work together in fighting this invisible enemy.