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expert reaction to Boris Johnson saying the UK will be capable of contact tracking 10,000 new COVID-1 cases a day by the start of June

During Prime Minister’s Questions today, Boris Johnson said that the UK will be capable of contact tracking 10,000 new COVID-19 cases a day by the start of June as part of the country’s test, track and trace programme.


Prof Eivor Oborn, Professor of Healthcare Management at Warwick Business School and an expert in healthcare technology, said:

“The goal of tracking the contacts of 10,000 new coronavirus cases a day by the start of June is feasible, provided everything works as it should.

“The app is currently being trialled, so the developer and NHSX need some time to make modifications to the software and algorithms that sit behind it. The people hired to do the manual contact tracing and the increased test capacity are in place, though the latter needs to expand further to accommodate all the new potential app users.

“The numbers are very important to the success of trace and track. The other key unknown is how well the technology actually works. If the Bluetooth signals do not transmit as predicted, then even those who are using the app cannot make the intended progress in terms of decreasing transmission.

“We still have not seen convincing evidence that the technical features associated with the app will work as intended. Also very little independent study or research about how the app might function seems to be in place to understand the use patterns as they unfold. Technology use generally brings in unintended consequences, and it is difficult to know what these will be.

“Manual tracing alone is too slow, and if there is a second spike it would be very difficult, if not impossible, to locate the contacts faster than the rate of new contacts are becoming exposed. The rapid transmission of the virus between people, is faster than the time it takes to do the needed detective work and phone calls to alert all exposed individuals. However, an app will not work on its own either, so best way forward would be a combined approach.”


Prof Rowland Kao, Professor of Veterinary Epidemiology and Data Science, University of Edinburgh, said:

“If there is going to be a reliance on an app to do at least part of the contact tracing, it has to be remembered that, in order for the app to identify contacts, it requires both the identified infection and the contact to have it – thus if 50% of the population is using it, that will only pick up 25% of the contacts on average – and initial uptake of similar programmes in other countries have been low. Therefore any voluntary use of the app would have to be supplemented by traditional contact tracing employing large numbers of people. As it is expected that all of these people will be newly trained, one should expect teething problems and therefore a considerable lag time before the contact tracing programme is as effective as it could be and when surveillance and testing will therefore play its biggest role in ensuring that infection numbers stay low.”


Dr Joshua Moon, Research fellow in sustainability research methods in the Science Policy Research Unity (SPRU) at the University of Sussex Business School, said:

“Overall, the idea is good. Contact tracing needs to be rapid and comprehensive to fully get on top of this outbreak. I’m not sure whether the app would be used here, but given the ‘army of contact tracers’ that was promised it might not be too necessary. This is especially given the security risks that researchers at GCHQ found in the app itself.

“The big issue, however, is the delay in test, track, and trace at all. I have my doubts that this target will be met, given the issues with the app and the need to train contact tracers. Even then, June 1st is delayed at best – this is a system which should have been in place before the pandemic even started. Accounting even for this, the system is delayed in its scale up.

“On top of this, the system needs an additional component: isolate. Testing, tracking, and tracing contacts and patients is not going to stop this pandemic unless patients are isolated, and contacts are tested and isolated. This system is going to have to develop as we go along, we need to pay attention to how well it works and adapt as we go along.”


Prof Keith Neal, Emeritus Professor in the Epidemiology of Infectious Diseases, University of Nottingham, said:

“We need to contact trace everyone who tests positive. With 21,000 contact tracers each working two days a week you will have 6,000 contact tracers working per day. Assuming they work 8 hours a day and they each are able to contact trace an average of 4 new cases a day then it would be easy to trace 24,000 new cases per day. The app’s importance is identifying possible contacts you don’t know the name of or contact details for e.g. that person you followed round when shopping.”


All our previous output on this subject can be seen at this weblink:


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