If its your own family and you know no ones got hep, cholera, covid, typhoid etc you should be fairly safe - make sure you wash your hands before your tea!
Municipal / communal systems on the other hand ⚰️⚰️ !
Would agree hepatitis is very nasty you can now be inoculated against all types.
I had it done few years ago when we did large upgrade/replacement of cast stacks and drainage job.
All completed a few weeks back - rather a lot of joins on the shower waste but it’s much smoother and more direct that the old setup which doubled back on itself rather unnecessarily with horizontal runs and little fall!