Different types of tests for COVID-19
24 March, 2021 | Raja
The COVID-19 Pandemic ambushed the world at the end of 2019 and the beginning of 2020. It frustrated several renowned organizations and individuals, as no cure was readily available. Infections were occurring at an increasingly alarming rate, and there was no solution to the problem in near sight. In the COVID-19 pandemic, while many people were competing in the race of finding an effective cure to the virus, many others kept researching to find effective ways to test the presence of the virus, in those showing symptoms.
Importance of Testing during the Pandemic
Symptoms for the COVID-19 virus differ from person to person. Some may have much more significant symptoms, and some may not realize they even have COVID-19. Testing for the virus's presence is essential to differentiate between affected people and isolate them timely. Countries that readily implemented effective and efficient testing techniQues had significantly lower infection rates than the somewhat relaxed countries in the process.
The UK and France are closer to each other in terms of population. The UK's population is around 68,126,222, and France's is approximately 65,370,939, which isn't too significant of a difference. Even though the infection rates in France when compared to tests per million with the UK may be lower, statistically speaking in terms of population we see from the graph below, that higher testing rates play an effective role in curbing the spread of the virus.
History of COVID-19 Testing in the UK
PCR Testing is widely used as a COVID-19 detection test. Dr Kary B. Mullis was the inventor of the PCR test. According to many resources and social media posts, he never intended for the test to be used for the detection of infectious diseases, instead, he designed it to pick up marks of DNA and RNA of the person being tested. However, there is little evidence of this quote.
The Public Health England announced PCR Testing on the 10th of January 2020. Initially, they committed one laboratory to the task, to perform all the tests implementing a centralized approach. It was later rolled out to 10 more laboratories around the 10th of February 2020. Currently, The Public Health services and several Private laboratories offer COVID-19 testings. With the increase in testing over 2020, infection rates have been reduced to a great extent in the UK. It has proved to be a bulwark in troubling times, as policymakers have shifted between implementing Phase 3 and Phase 4 lockdowns.
Types of Testings
There are three major types of testing that have been explored during the COVID-19 pandemic. These include the Serological Tests, the PCR Tests and the Antibody Tests. Let's dive deeper into how they work, and how they differ from each other. We'll also educate you on which test is suitable for which respective situation.
Out of the tests mentioned above, PCR Tests and Serological Tests are called Diagnostic Tests.
PCR stands for Polymerase Chain Reaction. PCR testing is also called molecular testing and has been one of the most widely used COVID-19 tests worldwide. PCR-Tests usually take around 24 hours for the results to get processed. Still, it can take longer depending upon where the laboratory is situated and the amount of workload they can manage. A swab is used to collect the sample from the back of your throat and then both your nostrils.
A RT-PCR Test can get the results before the process is fully complete. This quick turn around factor has played a pivotal role in ensuring the effectiveness of the 2-week quarantine policy setup by the UK government.
Serologic testing, better known as Antigen Testing, is another type of test that can help detect COVID-19 pathogens in the body. It uses a process similar to PCR Testing.
The sample is taken by swabbing at the back of your throat and up your nostrils. It is faster and easier to process but less accurate, hence it is also sometimes referred to as a Rapid Test.
As the name implies, antibody tests can determine whether or not there are antibodies present in your system. Having antibodies in your system does not guarantee "immunity".
The Antibody Test's purpose is to check whether or not you previously contracted the virus. It cannot tell you about the current situation of the body. The sample takes about 24 hours to get processed in the lab.
Difference between a PCR Test and a Serologic Test
Both PCR Tests and Serologic Tests are diagnostic tests, and even though an Antigen Test (Serologic) may be faster in processing the results, a PCR Test is still a much better choice. With a Serologic Test, there is a higher chance of getting a false negative if you get tested using this method. If the result comes back positive it is highly likely that it is correct. However, if you get tested five or seven days after contracting the COVID-19 virus, the test may not detect any Antigens present since their levels may be at an undetectable range, potentially leading to a false negative.
However, in the case of a PCR Test, even though the results take 24 hours to be produced, they are much more accurate than a Serologic test, and this is one of the many reasons that almost every country has adopted a PCR Test for the detection of COVID-19 Virus.