We are currently going into two years into the pandemic, and it may feel a little overdue to be discussing the symptoms of COVID-19 now. However, now more than ever with us returning back to “normal” it is important to be aware of the obvious signs we may sometimes miss. Testing alone is not enough to curb the spread of COVID-19, and it needs to be combined with testing the right people with symptoms specific and sensitive to COVID-19. Testing everyone is not feasible as it is a heavy cost to bear on the patient and also requires a lot of lab resources. Currently, the flu season is coming as well and differentiating between all the viruses that can affect our lungs and respiratory tract and COVID-19 may prove harder without some knowledge to look for.
Something commonly seen is that people only get tested after exhibiting symptoms, and this is even in the case of close contacts, many of which choose to stay at home after possible contact with a COVID-19 patient and only get tested once they themselves show signs of having an infection. This means that symptoms are almost always a predictor of an active infection, and is the single biggest prompt to get tested, whether it be self testing with an antigen rapid test or using the gold standard PCR.
From studies done based on the initial alpha variant outbreak in 2020, the most common symptoms were compiled based on their percentage of having a positive PCR test. It was found that loss of taste and smell were the single best indicator of a possible COVID-19 infection. After that was fever, a new and persistent cough, chills or shivers, loss of appetite and the last one being muscle aches. From this list, we can see that most of these symptoms are similar as any other respiratory illness such as the flu, which is caused by the influenza virus, something many of us used to get infected with during “flu season”. Now that most of us have already been fully vaccinated for COVID-19 and have levels of circulating antibodies, a symptom that may look and feel like a common cold may be something more serious such as COVID-19.
Knowing this, it should be common practice to get tested in the event that you experience any of the common symptoms of COVID-19 and you were in a situation in which you could have been exposed to someone with the virus. Antigen detection rapid test kits (RTK) that are readily available and suitable for home use can be used as first line testing if you suspect yourself of being infected. Should you have a positive antigen RTK result you should promptly get tested with PCR as it is significantly more accurate and can confirm the RTK’s validity. PCR can also determine your level of infectivity based on its mechanism of action. Briefly, Polymerase Chain Reaction (PCR) amplifies specific DNA from the sample by producing billions of copies and then testing for a very small specific strand, in this case COVID DNA. Antigen tests work to detect antigens, which are essentially any foreign substance that induce an immune response present in the body. Detecting an antigen in a sample from the RTK test uses something called immunochemistry. This detects a certain protein or chemical found on the surface of the virus, and this takes faster to do than the DNA replication process that is involved in PCR testing. PCR is the gold standard of testing and has the best ability to determine a positive result. This is why a negative RTK-Antigen result does not exclude you from the possibility of having COVID-19.
With us embracing the new normal, having responsible interactions with the people around us and making self testing a habit must be practiced by all of us. The key to breaking the transmission of COVID19 is testing and isolating positive cases in the early stages of the disease.