Doctors and teachers handle that, since they have regular contract with children. At least in my state they're required by law to report suspected child abuse.
As a side note, these laws are doing damage to organizations looking for volunteers that I don't think we have fully grasped yet.
People are willing to put a couple of weekends into making a middle school or high school competition happen. They're a lot less willing to do it if they have to go to an FBI station to get fingerprinted or produce a state and federal background check first. And I'm not talking about people with something to hide; I'm talking about people with a completely clean background who just don't want to be bothered.
