The number of new cases is a little bumpy.
The best website I have found is Sky's, but I cannot vouch for its accuracy.
Hounslow - where LHR is - has been single digit new cases for a few days. Slough - where some staff live is even lower. Bucks - which is more like Rupert territory, is a little higher, but is a big county.
https://news.sky.com/story/coronavir...daily-11956258