I’d never heard of the 48 rule until I had kids and have always gone back to work once I feel ok which in the case of a bug would be way before the 48 hours. I assumed the 48 hours just applied to kids as they are more likely to spread germs. I work in an office environment and it’s not something that’s ever been mentioned or enforced. Most people as far as I’m aware go back as soon as week well. Just asking as I’ve noticed the advice on nhs website is 48 hours for all.