An "Excel error" seems to be to blame for nearly 16,000 cases of Coronavirus not being reported or tracked in the UK. Public Health England said 15,841 cases between September 25th and October 2nd were left out of the UK daily case figures. "It was caused by some Microsoft Excel data files exceeding the maximum size and issues in transfer of data between NHS Test and Trace and PHE," the PHE stated.

PHE's interim chief executive Michael Brodie said the "technical issue" was discovered on October 2nd. BBC analysis found the number of cases reported in the area for the first week of October increased by 92.6% after taking in the missing tests.

According to a BBC article, the root cause of the error came from the "ill-thought-out" use of Excel software. The PHE had set up an automatic process to pull test data into Excel templates which were then uploaded to a central system that was made available to the NHS Test and Trace team and other government computer dashboards.

The problem arose when the PHE developers used an old file format of excel (XLS) that can only handle 65,000 rows of data vs. the 1 million rows Excel can handle with the moder XLSX file format.

"Each test result created several rows of data which meant that each template was limited to about 1,400 cases. When that total was reached, further cases were simply left off."

Just to be clear, the UK government was tracking Covid cases in Excel... EXCEL! Now, I love Excel but I love it well enough to realize that it's no place to keep a country's Coronavirus tracking data.

Don't worry, as of writing they have now resolved the issue by splitting the Excel files in order to hold more data:

Sending thoughts and prayers to the person managing this Excel file. I truly hope it doesn't crash or get stuck in a circular reference error anytime soon.