Public Health England (PHE) said a technical issue resulted in 15,841 cases between September 25th and October 2nd being left out of the reported daily coronavirus cases.
Senior officials said the outstanding cases were transferred to NHS Test and Trace “immediately” after the issue was resolved and thanked contact tracers for their “additional efforts” over the weekend to clear the backlog.
All cases were passed on to tracers by 1am on Saturday, meaning potential delays of more than a week in contacting thousands of people who were exposed to the virus and telling them to self-isolate.
The technical issue – caused by some data files reporting positive test results exceeding the maximum file size – also means that daily totals reported on the UK government’s coronavirus dashboard over the last week have been lower than the true number.
For example, 4,786 cases which were due to be reported on October 2nd were not included in the daily total on the dashboard that day, when the figure was given as 6,968.
The government’s dashboard said that, as of 9am on Sunday, there had been a further 22,961 lab-confirmed cases of coronavirus in the UK, bringing the total number of cases in the UK to 502,978.
A note on the dashboard said: “The cases by publish date for October 3rd and 4th include 15,841 additional cases with specimen dates between September 25th and October 2nd – they are therefore artificially high for England and the UK.”
Michael Brodie, the interim chief executive at PHE, said the “technical issue” was identified overnight on Friday, October 2nd in the data load process that transfers Covid-19 positive lab results into reporting dashboards.
“NHS Test and Trace and PHE have worked to quickly resolve the issue and transferred all outstanding cases immediately into the NHS Test and Trace contact tracing system and I would like to thank contact tracing and health protection colleagues for their additional efforts over the weekend,” he said.
Test and Trace and Public Health England joint medical adviser Susan Hopkins said: “All outstanding cases were immediately transferred to the contact tracing system by 1am on 3 October and a thorough public health risk assessment was undertaken to ensure outstanding cases were prioritised for contact tracing effectively.”
PHE said NHS Test and Trace have made sure that there are more than enough contact tracers working, and are working with local Health Protection Teams to ensure they also have sufficient resources to be urgently able to contact all cases.
The number of call attempts is being increased from 10 to 15 over 96 hours.
Shadow health secretary Jonathan Ashworth said: “This is shambolic and people across the country will be understandably alarmed.
“Matt Hancock should come to the House of Commons [today] to explain what on earth has happened, what impact it has had on our ability to contain this virus and what he plans to do to fix test and trace.”
On Saturday, Professor Graham Medley, an attendee of the Scientific Advisory Group for Emergencies, tweeted: “Reporting delays play havoc with data streams and make them very difficult to analyse in real time.
“If the delays change or vary by group then they can distort a lot. Wonder what these will do to the R estimates next week”
