Are we testing and tracking the right people?

Much fanfare has been made by the UK Government about its test and trace system for Covid-19. Back in the summer the Prime Minister Boris Johnson expressed it would be ‘world class’. But how effective is the system at reducing and stopping community transmission?

You can book a free test through gov.uk but the booking system explicitly says ‘You cannot get a free NHS test unless you have symptoms’. It adds this rule applies even if:

• you live with someone who has coronavirus
• you’ve had close contact with someone who has coronavirus
• you’ve come to the UK from a high risk country

In an attempt to understand the numbers of people in the community with Covid-19, the Office for National Statistics (ONS) has an infection survey. They contact households (at random) and ask them to participate in testing. The advantage over the test and trace system is picking up cases where no symptoms are present.

In the latest report, the ONS writes “In the most recent fortnight, 34% of those who tested positive for COVID-19 reported any evidence of symptoms at the time of their test”. Data shows this is a trend consistently seen since it started the data collection back in May although it was actually lower through the summer months.

So, what does this mean? If two-thirds of people testing positive for Covid-19 have no symptoms they will never be picked up by the test and trace system. The majority of people with the virus would be walking around the community unaware they have the virus. This identifies a fundamental flaw with the current system.

The former health secretary Jeremy Hunt has previously said population testing is the only sustainable solution. The data from ONS suggests this may be critical in the absence of a vaccine.

Much criticism has been labelled at the test and trace system for not reaching contacts of those who have tested positive. Latest data shows around 1 in 4 people are not traced where contact details are available. But this may only be a small part of the problem if many people with Covid-19 don’t enter the testing system in the first place.