My daughter, age 16, was looking up HIV last week on the internet. As a result, she has absolutely lost her marbles and become totally convinced she's got AIDS. She says she is a virgin and has never used injectable drugs. Also, she has never had a blood transfusion. So could she really have caught this disease?

It's almost impossible. I quite often see people who are convinced they have AIDS but who are in reality perfectly okay. Sometimes it's necessary to do a blood test to convince them they are wrong. My advice would be to take your daughter to your GP for a commonsense chat -- and perhaps a test.