Everyone who has had contact with the child in at least the last two weeks, and preferably, during the past month should be notified. Contacts should include the school nurse, daycare director, camp counselor, or other individuals in the position to assist you in notifying and checking those that your child has had contact with.

Yes, they should be checked if they have been in contact with an individual who has an active infestation. Age does not make you immune from having lice.