19th June 2020 by Anne Sakoane
That was the powerful message from the
Director-General of the World Health Organisation (WHO) on 16th
March 20201, exactly 1 week before the UK went into lockdown. But
why is testing so important? What happens if there is not enough testing? And
how can testing be carried out efficiently?
The SARS-CoV-2 virus that causes COVID-19 has torn its way across the world. The fact that this is a new virus we know very little about, makes it that much harder to study, to understand and to overcome. But something that helps in this pandemic, and any other pandemic, is testing. Testing instantly lights up the coronavirus’ location on a map like a beacon and tells us two things:
Without testing, we don’t know where the coronavirus is, how far it has spread or how to effectively stop it. In these cases, communities are essentially forced to implement blanket-wide quarantines in an attempt to slow the spread of the coronavirus: if we cannot physically interact with others, the coronavirus also cannot physically interact with others.
This may sound like an effective strategy, but it has been argued that these large-scale non-pharmaceutical interventions might have lasting societal and economic implications2. To combat this, widescale testing can help alleviate those pressures.
So, we know that testing is important and in an ideal world, we would want to test anyone and everyone. But realistically that would be almost impossible; there would be a physical limit on the number of tests available and a limit on the capacity of testing facilities.
There is no doubt that we first need to test those who present with symptoms. Then, we should proactively test those who symptomatic patients had contact with as there is a possibility that they might be asymptomatic but still unknowingly transmit the virus. Positive cases identified from the second round of testing should then be isolated. This is the basis of ‘contact tracing’ also known as ‘test and trace’, a technique implemented in many countries including South Korea, Italy and now England4. The solution usually takes the form of a digital app that runs in the background of your smartphone and you will be alerted if someone with a COVID-19 diagnosis has been in sufficiently close contact with you (the functionality of these apps varies).
By implementing contact tracing supplemented with widescale testing, communities are able to take a more targeted approach to disease management, help redirect healthcare services and resources appropriately, and ultimately ensure that the virus is contained and healthcare systems are not overwhelmed (in other words, to flatten the curve).