A technical glitch has resulted in 15,841 positive cases of coronavirus not being counted in the official daily of COVID-19 log in the past week, England's health authority has admitted.
Public Health England (PHE) said the issue had been identified overnight on Friday, and a rapid investigation calculated the list of cases that had gone unreported between September 25 and October 2.
However, its chief sought to reassure the British public on Sunday that each of those who had tested received their COVID-19 result as normal and were advised to quarantine as per the current rules.
"A technical issue was identified overnight on Friday 2 October in the data load process that transfers COVID-19 positive lab results into reporting dashboards. After rapid investigation, we have identified that 15,841 cases between 25 September and 2 October were not included in the reported daily COVID-19 cases," said Michael Brodie, Interim Chief Executive of the PHE.
"Every one of these cases received their COVID-19 test result as normal and all those who tested positive were advised to self-isolate," he said.
Amid mounting criticism, the health authorities stressed that the National Health Service (NHS)-run Test and Trace system for coronavirus had worked to quickly resolve the issue and that the processes have been made further robust.
"We fully understand the concern this may cause and further robust measures have been put in place as a result," Brodie said.
NHS Test and Trace, and PHE Joint Medical Advisor Susan Hopkins said the majority of the missing cases occurred in recent days, between September 30 and October 2, and that the glitch did not impact the basis on which decisions about localised lockdown action were taken last week.
"All outstanding cases were immediately transferred to the contact tracing system by 1 AM on 3 October and a thorough public health risk assessment was undertaken to ensure outstanding cases were prioritised for contact tracing effectively," said Hopkins.
"The advice remains the same. If you have tested positive you must self-isolate immediately for at least 10 days from when your symptoms began and we urge everyone who is contacted by NHS Test and Trace to provide details of their recent contacts," she said.