Aww Belle poor Julia!!!!! Never nice to be bitten.
If it had happened to DS (and no doubt it probably will - or HE will be the biter) I don't think I would take him out of day care. But I'm very happy with the daycare that he is in, the carers all love him, and tell me what a good boy he is, he's so cruisy and how much they all love him and think he's gorgeous. So even though they have to watch so many kids at the same time, I think they try their hardest to make sure nothing like that happens, but I can't expect it NOT to happen IYKWIM? Kids move quickly!!! Oh, and DS gets sick all the time too, as you know, he has just gone through tonsillitis again - and has three ear infections since he started going. But, I just think its building up his immunity, and it won't last forever.
Make the decision that YOU feel most comfortable with, after all, she's your baby!!!