It's good to tell the camp nurse because they may already be sexually active or considering it, and as campers are under 18, They could probably use "the talk" from someone they may take more seriously than their parents (who may or may not have had a really serious conversation about it - mine wasn't). Also, they may have been sexually abused, and that's something the nurse has to consider.
Other than those, I think it's also good to listen before taking them to see the nurse, and letting them know that you're there to help them, and that they can trust you, and then tell them WHY you have to take them o the nurse (the whole confidentiality contract thing that we're all probably well aware of).
