In Great Britain, Corona case numbers were underreported for several days due to a data mishap that occurred when using the Microsoft Excel program. An overfilled Excel sheet is said to have been the reason for the loss of the test data. How did this happen?

In Great Britain, the "test and trace" unit of the NHS (National Health Service) is responsible for sending the data for those who test positive for Covid-19 to the responsible health authority PHE (Public Health England). As the British Guardian reported, the authority had compiled and managed the case numbers in Excel spreadsheets since the beginning of the pandemic.

Excel can only be used as a database to a limited extent, as the number of available rows in the software is limited. In the current Excel version, up to 1,048,576 rows can be entered. In this case, the limit was only 65,000 rows due to the use of an outdated Excel format. As a result, when importing the CSV file sent by the NHS with the 16,000 Corona cases submitted, the excess rows were deleted for a total of 15,841 cases. This resulted in the UK corona statistics looking better for a few days as well as infection chains not being followed up on.

The example shows that when importing data, it is important to ensure that both the data format and the software can handle the type and scope of the data correctly. If possible, the latest version of software and open formats should always be used.