After a few years with each kid in daycare, we've seen a few sicknesses sweep through all the kids there (I put a star next to the one our son got - our daughter actually only ever caught colds, as far as I can remember):

* Roseola *
* Fifth's Disease
* Coxsackie/Hand Foot Mouth
* Herpes Simplex Virus 1 *
* Conjunctivitis/Pinkeye
* RSV/Respiratory syncytial virus * (he got this one before he started daycare)
* Colds *
* Flu

The kids got sick a decent amount, but now they have pretty strong immune systems! I don't know if there's a direct correlation, or if all kids just get better immune systems over time.

How about you: what sicknesses did your kids pick up at daycare?