Since the pandemic began, a new normal has taken hold of the world. Now, we are far more inclined to meet up outdoors and far more clued up to what can make a difference in the fight against Covid. As a result, we all wash our hands more, stand a good distance from strangers and open windows in our homes to let fresh air in. And, of course, many of us are still wearing masks even though they are no longer mandated. The hope of all of this is to come into far less contact with a large amount of Covid particles that could infect us.
Another concept that we are far more used to and familiar with than ever before is regular testing. In the fight against Covid, one of the ways the Government has tried to keep numbers down is to ramp up testing capabilities so that areas with high concentrations of the virus could be identified. The hope was to be able to open up society in areas where tests were showing that there were far fewer infections.
It has now got to the point where we can test ourselves at home or easily find a testing centre only a few miles from our front doors. But what are the tests that are now available? And what are the key differences between the two? And in what instances do you use each one?
These are all exceptionally common questions that we look to answer here.
A lateral flow test is sometimes referred to as a rapid test or an antigen test. It works by identifying proteins, or parts of proteins, that are only found in COVID19. They are conducted by taking a sample from a patient’s tonsils and/or in their nostrils with a swab. That sample is then placed in a liquid and applied to testing paper to see whether those proteins are present. Lateral flow tests take about 15 to 30 minutes to complete.
To get the best use out of lateral flow tests, it is best to use them either when you have symptoms of COVID19 or to use them regularly. To get the most accurate results, it is best to use them twice a week if you are simply testing to ensure that you and your household are virus-free. Doing so means that going to public spaces, places and events, can be done with confidence that you will not be infecting others - especially if you are fully vaccinated. Many events may ask you to do a lateral flow test before attending, but for your own good it can be a good idea to do a lateral flow test just after you have come back from a highly populated space.
If a person carries out a lateral flow test twice a week, the likelihood of receiving an accurate result as to whether they are positive or negative is much improved. That is because a newly infected person has a higher viral load that is easier to pick up with the testing apparatus when the viral load is more concentrated. If a lateral flow test is taken even two weeks after a person has been infected with the virus, the chances of the test coming back with an accurate positive reading are much diminished. That’s why the Government recommends testing twice a week to ensure that any new infections are caught as quickly and accurately as possible.
PCR tests are conducted, initially, in the same way as lateral flow tests. A sample is taken from a person’s tonsils at the back of their throat, as well as up their nose. However, as opposed to testing for the disease there and then, that sample is then sent off to a lab to be checked.
Like a lateral flow test, you can get a PCR test done if you are suffering from symptoms of COVID19. Or, it can be a good idea to have a at home PCR test done if you have completed a lateral flow test that comes back positive. Doing so will confirm with a high degree of accuracy whether you have the virus or not. It is also highly recommended that you take a PCR test if you know you have come into contact with a person who has a confirmed case of COVID19.
Finally, even though requirements are constantly changing, PCR tests are often what many countries require you take before entering.
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Of the two types of test, PCR tests are far more accurate. Not only is that down to being conducted in lab conditions, but the way the presence of the virus is tested is also different. PCR tests involved heating and cooling samples in the presence of reagents. Doing so changes the virus’s RNA into DNA which then allows for genetic sequencing to take place - as well as identifying whether a person has COVID or not.
There is a time and a place for both types of tests. For, while PCR tests are highly specific and accurate, they are time-consuming so that in the long run, normal life is difficult to resume. Plus, there is the trouble of capacity. As PCR tests need to be conducted in a lab, it is impossible to test the entire population twice a week (or however regularly) to ensure that all cases of COVID19 are identified to help break chains of transmission.
Lateral flow tests, on the other hand, may be less accurate - but if conducted regularly enough they can be a very helpful tool in controlling the disease.