Why Testing Matters

As I noted yesterday morning, testing is at the heart of the WHO procedures for dealing with the COVID-19 pandemic, and it is rather disappointing that both the UK and Scottish Governments are still choosing to ignore this. We are already reaping the consequences of this, and it will rapidly snowball.

Why is WHO so emphatic about the need to test, test, test? I can think of at least four good reasons:

  1. Computer models are only as good as the data they are built from. If the data is poor, so will the predictions, and any policies built on them. Not testing means poor models and no idea what to expect next.

  2. Not testing all suspected cases leads to unnecessary self-isolation. This has become particularly acute with the new 14-day household isolation policy, due to which a large number of NHS and other critical services workers have not been able to go to work today. How many of these would have been able to work if their unwell family members had been tested?

  3. Currently there is no test to tell if a person has had the infection and recovered. UK officials are assuming once recovered we will have some immunity, meaning we could return to work, not need to self-isolate if other family members develop symptoms, etc. But without being tested while ill, we won't be able to tell, and so end up in an endless circle of self-isolation.

  4. There is emerging evidence from the Chinese data that suggests that majority (perhaps as much as 90%) of all infections are spread by people who are asymptomatic. If this is the case, there is absolutely no way to get the spread under control without testing.

In other words, we can neither control the spread of the virus, nor keep our society working unless we follow the WHO guidelines and test, test, test.