The Independent SAGE welcomes the government’s decision to release the first figures from its Test & Trace system but it is extremely concerned that it is picking up contacts from only 25% of estimated symptomatic infections.

The government’s own SAGE committee says that 80% of the contacts of all symptomatic cases must be found and isolated in order to stop the virus spreading further.

According to the committee’s calculations, the government’s Test and Trace picked up only one quarter of cases in its week, well below what is required to manage the spread of the virus. 

Independent SAGE report on Test, Trace and Isolate, released on Tuesday, argued that the current system is not fit for purpose. This has been borne out by the figures published today. The start of any system The system is still in its infancy and, as currently constituted, is not ready to support the current wider relaxation of the lockdown rules. This risks future spikes if not addressed urgently.

The committee’s report, chaired by Sir David King, urged the government to radically overhaul the current system and to pass the management of the Test and Trace system – which it says should be renamed Find, Test, Trace, Isolate, Support – from private contractors to local public health directors. 

Independent SAGE analysed the figures released today that showed 8,117 individuals testing positive for COVID-19 between May 28 and June 3 were referred for contact tracing. Only 5,407 (67%) were reached and asked to provide details of recent contacts. ONS surveillance data however suggested that there were at least 23,000 new symptomatic cases during that time period, meaning that only about a quarter of symptomatic cases had been found by the Test and Trace system.

Matt Hancock said today that 85% of contacts had been traced. This is deeply misleading as it relates only to the 5407 individuals who were reached by contact tracers and ignores the 75% of new cases that were simply not found. 

Sir David King, Chair of Independent SAGE said: “It is of course reasonable to expect that the first week of a new programme like this will have teething problems however these figures are alarming. What is of particular concern is that we are continuing to see the country coming out of lockdown before a fit for purpose – let alone world beating – Test, Track and Trace system is up and running.”

The full Independent SAGE Interim report is here


Independent SAGE has linked together some of the disparate sets of available data to provide an interpretation of the latest Test and Trace report. 

We have placed these data in the context of the daily reported cases at the Govt press conference, together with the estimated total number of new infections per day from ONS surveillance data.

The press conferences have identified 13470 total new cases between 28/5 and 3/6. Based on these figures only 40% of the cases were asked to identify contacts. However, ONS surveillance estimates 35000 new infections during this period ( with or without symptoms). If we assume 60% of these infections were with symptoms, and therefore eligible for a test, then those contacted by the T7T system represented only 26% of all estimated symptomatic infections.