David Davis is a former Secretary of State for Exiting the European Union, and is MP for Haltemprice and Howden.

One of the starkest facts about the about the global coronavirus pandemic is the sharp difference between the infection rates in the Western nations and the Asian countries.

Given the proximity of South Korea, Hong Kong, Taiwan and Singapore to China, you would expect them to face overwhelming number of cases and very high mortality rates. In practise their total deaths amount to about 270 out of a total population of about 88 million. The major part of this difference is accounted for by a completely different strategy, in which “track and trace” was a key part.

So I was a little surprised by the Government’s reported intention that it won’t start our track and trace scheme until the currently infected numbers have dropped to 100,000. The best, albeit unreliable, estimates, put the number at 300,000-400,000 at the moment.

That number is declining, but that fall is likely to flatten out when the lockdown is relaxed and people start travelling and working again, no matter how careful we are. We may not get to 100,000 this side of the summer.

The simple truth is that the sooner we start track and trace, the faster the numbers will come down. Imagine that we have an infected population of 400,000. Obviously, we would like to be able to trace all the contacts that all of these people have had.

But if we can only track 100,000, we are still going to be able to find maybe 100,000 newly infected people (if R0 = 1), and get them, at very least, to self-quarantine, thus protecting their families, friends and workmates, stopping the infection of the next 100,000 (or more).

This will drive the numbers down faster than would happen without a track and trace scheme. Or, just as important, stop the numbers rising when we relax the lockdown, and avoiding a second or third lockdown.

So, irrespective of the current state of infections, we should start now.

What was also surprising was the Department of Health’s judgement that they needed just 18,000 trackers to do the job. The USA estimates that it will need 100,000 to 300,000 people to do it. Scaled back to our size, that is between 20,000 and 50,000 people. Given what is at stake, the obvious judgement is to go for the higher number to get the job done faster. Lives are literally at stake – so skimping on this would be unwise in the extreme.

Not that it should cost very much. We have supposedly had 750,000 volunteers to help out the Government. Four million people are on furlough. It should be very easy to get 50,000 volunteers to help with the practical tasks involved in the track and trace procedure, or 100,000 if people are willing to do it part time. A volunteer army of 100,000 trackers would allow us to turn around this problem in a way none of the strategies to date have done.

Despite all the talk of phone apps and high tech procedures, we should be in no doubt that most of this work is done by human interview. In Singapore, for example, only 20 per cent of the population downloaded the app, so the rest had to be followed up by human intervention.

Some of the task will be quite technical, but the high volume work will be comparatively straightforward. Mostly, it will involve interviewing infected people about their day to day movements and contacts over the time from a few days before their symptoms started, and inputting that data into a central database.

For safety’s sake, the interviews will likely be carried out over a telephone anyway. So the training will be comparatively straightforward, and the task could be done from home.

It has been suggested that this can be coordinated by local government, and this probably is wise. Public Health England was not designed for this task, nor were its staff trained to cope with the enormous crisis management exercise that they are now immersed in. Despite the huge efforts of its people, as an organisation it has struggled to cope with the huge burdens put upon it. A much more decentralised approach would almost certainly work better.

Similarly, the Government should delegate as much of the notification exercise to the telecommunications companies as it possibly can. They carry vast amounts of data about telephone location data already (without any app), and they are best placed to do an Asian-style exercise of text notification of everybody who’s been in a given at risk location at a given time, telling them to get a Coronavirus test because they have been exposed to infection.

Which brings us to the real limitation, which is the ability to test people who have been exposed to the virus. The Department of Health will need to keep ramping up the testing capacity once it gets to its 100,000 target, at least to the Prime Minster’s 250,000 a day or beyond. To date, Italy has done 1.85 million tests. We have to do better than that. By comparison with the economic impact of not doing it, the cost is trivial.