It all depends. My twins were got HFMD from their classmates twice within 2 months, despite the school carrying out monthly sanization, daily cleaning/sunning, etc. If other kids got it from outside school and come to school, there's nothing much can be done about it. I burnt all my leave those 2 months. They were having running nose practically every other week. If not, it will be cough. That was in the initial months. Then they got a bit stronger, so when someone in their class has a cough/running nose, sometimes they do not catch it. I keep them clean every day by sanitising their bags, changing towels, sunning their school stuff, beefing them up with Vitamin C and water. Mine have not bee toilet trained yet although they are coming to 28mths. They are ok at home but once go to school, they back to diapers. So got to work with teachers closely.Guess it is part of growing and pain for working moms like us.