Testing our patients (and our patience): Coronavirus tests
It felt like the glimmer of light at the end of the dark lockdown tunnel when we first heard about the development and subsequent availability of tests for COVID-19.
But as time rolls on and their efficacy and accuracy are called into question, it feels at times that instead of testing our patients, they are really just testing our patience.
Having said that we must look for the small victories during a testing time like the present. Surely the fact that tests (dubitable accuracy or not) even exist is a reassuring sign and a step in the right direction.
And even the fact that we have two different tests with different purposes can only be seen as a positive during this pandemic, which so far has just brought doom, gloom and doubt.
Here we explore the different types of tests and how effective they actually are.
Antigen testing – finding the virus
Perhaps the most impactful form of testing is the Antigen variety, which is the method of choice so far of the NHS.
It works by looking for the genes of the virus in samples taken from swabs of the nose and mouth.
However, the drawback is that it can take days to report results, which can make it more difficult to stop the spread of infection.
Scientists have been trying to develop a new rapid test that does the same thing with roughly as much accuracy but a lot more speed. This would help towards slowing down the rate of infection by informing carriers sooner.
It would still work the same way as the existing test by analysing swab samples, but scientists are hopeful that they can develop it so that it works with saliva swabs as well as the traditional mouth and nose swabs.
Another test that also identifies if you are presently carrying coronavirus works by searching for and identifying the spikey protein on the virus shell. This is a much more simple and quick test however the catch is that it only works if you are carrying a significant amount of the virus. Though this is reassuring that a fast and easy test exists that can detect the virus, it means you’d have to be carrying a tangible strain to be found, so it won’t go into overdrive searching for the virus genes themselves.
Essentially it is a simple bedside test, best for confirming, as opposed to finding, the infection in those with pre-existing symptoms (those who likely know they already have it.)
However this is not helpful for those cases where people carry the virus without physical symptoms.
It’s easy to forget that if the virus is there you are still infectious whether you have symptoms or not.
Antibody testing – Proving an infection has occurred
Unfortunately there are a lot of us who don’t even realise that we currently or previously have had coronavirus, and it’s for this reason that the antibody test exists.
The test works by looking for the antibodies specific to fighting the disease and does so by searching for their presence in the blood (which is subject to the intensity of the immune response and the time since the infection.)
Whatever the initial response the amount of antibodies in the blood drops over time, eventually to very low levels that can be quickly boosted again since the body has seen the infection before.
Unfortunately COVID-19 is too new to fully understand how the human immune system reacts to the virus over time. If an antibody test is negative it may just be that the infection is either too recent or too old to trigger the test
The sweet spot to detecting antibodies is around two weeks from the first symptoms, which means that if you had an infection 2 months ago the chances of detecting antibodies are significantly reduced.
This especially applies to cases where the carrier had no symptoms and therefore the body’s response was very mild and more difficult to detect.
The test works by using a blood sample or a finger prick of blood to identify if antibodies are present.
It may seem straightforward enough but there has been a lot of politics and debate concerning the efficacy of the finger prick test whilst it is largely accepted that the blood sample route is 100% accurate.
However both statements are rubbish…
If either test finds antibodies then it is highly unlikely to be wrong and even more likely that an infection has occurred in the person in question.
But to make things more complicated – if no antibodies are detected then things are pretty much up in the air.
It could be the case that an infection is in its very early stages and has not yet triggered a response, or it might be the case that the infection happened so long ago that the antibody levels are no longer detectable.
So in conclusion exactly how accurate are the tests?
In general terms if any of the tests say that someone has had an infection then it is very likely to be right.
In fact this is such the case that it is largely agreed that the likelihood is as high as 90%+ if the results come back positive.
Whereas if the test is negative it doesn’t really tell you all that much!
The virus might be present but the swab could have missed it (this happens in about 1 in 3 test!), or it could be the case that you have previously had the infection but now your antibodies are too low to detect.
The most pressing question on everyone’s lips seems to be – If you have had COVID-19 can you get it again?
Unfortunately we don’t know for sure yet as this is all very new and inconclusive!
Logically speaking, it’s likely that an infection will provide some future protection, but we don’t know how much or for how long.
It might mean that you can catch it again but more mildly, or on the other hand you could find yourself with just as severe a reaction as before. We simply don’t know yet.
These are all challenges any future vaccine will have to overcome in order to be effective.
But in the meantime the biggest mistake to make is to assume that a positive or negative test result is a statement of fact.
The single most important point to understand is that a Government swab at a drive-through centre or any similar testing service will only detect the virus in about two thirds of infected people. A negative throat swab does not mean you are not infectious!
Although if you get classic COVID-19 symptoms and are then well again after 10 days of isolation then you can be pretty confident that you no longer pose a COVID-19 risk to others this year.
A testing situation: Final thoughts
Though we find ourselves in a testing situation as we wait for a foolproof test (if such a thing exists) to emerge on the market, it’s not all doom and gloom!
It may feel like we’re in a bit of a limbo as we wait to learn of how protected we are by our own antibodies, but there are other ways to ensure your protection from the disease – like your own body!
Investing in a healthy lifestyle with a nutrient dense diet and plenty of physical activity will help safeguard you against contracting the more severe symptoms
It’s widely documented that the most extreme cases of COVID-19 have been linked to obesity and poor physical health, so equipped with that knowledge we know that we can actively work towards preventing ourselves from becoming another statistic.
And that is where we at CorLife are here to help. We fully adhere to the principle of a varied diet and active lifestyle being not only pivotal to, but necessary for our mental and physical health.
Our programme provides businesses and their employees with the tools to ensure a healthy, happy and productive workforce – so instead of being so dependent on the timeline of tests, we can live our best and most healthy lives by taking control of what we put into our bodies and how we move them!