When I started working with children 8 years ago, the first 2 years were spent catching everything under the sun, including conjunctivitis, ring worm, colds, stomach bugs. Trust me, you name it, I caught it.
The trouble is, some parents won't come to collect their children when requested to, some even go as far as giving fake numbers to the nursery so cannot be contacted anyway.
I think it is swings and roundabouts in some places. For example, I won't stand for an ill child in my unit, yet my manager is always reluctant to send an ill child home. One child was so ill just before Xmas that his parents had to rush him to hospital, but he was back at nursery the next day, suffering and terribly poorly. I had to harrass my manager for three hours before she would make the call home and then when she did, we still had to wait until the end of the day for the child to be collected, as his parents wouldn't leave work before their finish time.
Not all nursery staff are poor in the hygiene department though. My unit (and I swear this is all true!) clean noses non stop (we don't wear gloves, we would be in them all day!), we disinfect and sterilise toys and equipment weekly and we wash all our soft toys, cushions, fabricy things weekly. Obviously bibs and flannels are cleaned daily, bed mats and cots are wiped after every use with sterilising solution. There is only so much we can do and still the children are coming down with everything going!
It's part and parcel of nursery life IMO.