Winnie,
Your not alone, we are all here. I know it's not the same, but we are here. Someone knows something and they will talk and tell other kids then one will tell the right person. If they couldn't tell he was sick that is a good sign that he is holding up so far, I know that don't make you feel better, but his higher power is watching out for him. The clock is ticking and he will be found soon, like you said as word gets out no one is going to want to get caught with him, even his so called friends.