Where did the missing 16,000 positive coronavirus tests come from?

Ross McGuinness
·3 min read

Watch: Error caused UK to miss over 15,000 COVID cases

The rate of new coronavirus cases has risen dramatically in several parts of England after almost 16,000 previously unreported positive tests were eventually added.

The government has been left embarrassed after it emerged an IT glitch, reportedly caused by an Excel spreadsheet, meant 15,841 COVID-19 cases were missing from daily totals.

Public Health England (PHE) said cases between 25 September and 2 October were mistakenly omitted, causing delays to efforts by NHS Test and Trace to find the contacts of those who tested positive for the virus, in some cases by a week.

On Monday, Boris Johnson was unable to say how many contacts of positive coronavirus cases had been missed as a result of the mistake, while a government minister said: “We can’t change history”.

Watch: Boris Johnson unable to give figures after glitch

The Press Association (PA) reported that the problem was caused by a Microsoft Excel spreadsheet reaching its maximum file size, which prevented new names being added in an automated process.

PA reported that files have now been split into smaller batches to prevent the error from happening again.

PHE said the issue was caused by some data files reporting positive test results exceeding the maximum file size.

It said the outstanding cases were transferred to NHS Test and Trace “immediately” after the issue was noted and all cases were passed on to tracers by 1am on Saturday.

In an analysis of case numbers after the missing tests were added, PA found that Manchester now has the highest rate in England, with 2,740 cases recorded in the seven days to 1 October – the equivalent of 495.6 cases per 100,000 people, up from 223.2 in the previous week.

Members of the public wearing face coverings to help prevent the spread of the coronavirus pass a Keep your distance COVID-19 public information display on 4 October 2020 in Slough, United Kingdom. Slough Borough Council confirmed on 2nd October that its coronavirus infection rate is the highest in the south of England and Slough MP Tan Dhesi asked Health Secretary Matt Hancock in Parliament whether the local test centre in Montem Lane could be reverted to permit walk-in and drive-in visits without an appointment. (photo by Mark Kerrison/In Pictures via Getty Images)
There have been coronavirus spikes in a number of parts of England. (Getty Images)

Liverpool has the second highest rate, up from 287.1 to 456.4, with 2,273 new cases, while Knowsley in Merseyside is in third place, up from 300.3 to 452.1, with 682 new cases.

The analysis, based on Public Health England data published on Sunday night, also shows sharp rises in Newcastle upon Tyne, Nottingham, Leeds and Sheffield.

Dr Duncan Robertson, lecturer in management sciences and analytics at Loughborough University, said the error was “an absolute scandal”.

He tweeted: “These individuals will not have had their contacts identified and those contacts may have become infectious and may have been spreading the virus.”

Paul Hunter, professor of health protection at the University of East Anglia, told BBC Radio 4’s Today programme “there will be occasional glitches” in a system this size, but added: “I think the thing that surprised me was the size of it – almost 16,000 results going missing over the course of a week is quite alarming I think.”

Samples are taken at a coronavirus testing facility in Temple Green Park and Ride, Leeds, as NHS Test and Trace - seen as key to easing the lockdown restrictions - is rolled out across England.
Almost 16,000 positive coronavirus tests went missing after an IT glitch. (PA)

Rowland Kao, professor of veterinary epidemiology and data science at the University of Edinburgh, said the contacts of those affected will “have already contributed extra infections which we shall see over the coming week or so”.

Asked how many contacts of positive coronavirus cases had been missed as a result of the error, Johnson said: “I can’t give you those figures.

“What I can say is all those people are obviously being contacted and the key thing is that everybody, whether in this group or generally, should self-isolate.”

Shadow health secretary Jonathan Ashworth said the error was “shambolic”, adding that “people across the country will be understandably alarmed”.

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