I guess my issue is the mums who are the all for one thinkers so don't with hold their children when they are obviously sick and sniffly, and assume all other mothers are the same.
Gosh I never took Alexzander to mum's grup when he was sick (or anywhere for that matter) but allowed his toys to be shared around at mum's group. I wouldn't want his sick germs shared around but didn't have a problem with having a bit of drool shared. That said, if another mum didn't want him to play with their child's toy I would tell him no & take it off him.