Question: Can you catch AIDS by tongue kissing?
One-line questions such as this, scribbled on a scrap of paper, indicate to me that the public education about AIDS still has a long way to go!
NO. You cannot catch AIDS from kissing—no matter how passionate. AIDS cannot be caught by any form of casual encounter. It cannot be caught 1 shaking hands, by a cough or sneeze, by dirty toilets or by spa baths. It theoretically possible, although unlikely, to catch AIDS from oral sex.
Normal intercourse and anal sex, as well as any method of transfer of contaminated blood products from one person to another (eg. a shared needle) are the only methods of AIDS transmission. Injections given by doctors or dentists are given using needles that are used once only. Even ear piercing is done by the use of stud guns that cannot transmit AIDS.
AIDS is quite a difficult disease to catch, but if you are promiscuous in your sexual habits, or are involved with illegal drugs, your chances increase dramatically. Condoms offer some protection against AIDS, but not 100% protection because they can burst of come off at the wrong time.

Question: How can you actually catch AIDS? I see all the advertisements, but I worry that it might be easier to catch than they say.
You can catch AIDS (acquired immune deficiency syndrome) by sexual intercourse with a man or woman who is already carrying the AIDS vitus (human immunodeficiency virus—HIV), by receiving blood from such a person, or by using a syringe needle previously used by a victim.
It can be transmitted by a person who is showing no signs of the disease, and may never develop the disease, but who carries the vitus.
It can NOT be caught by other forms of body contact including kissing. It is not highly contagious, and is actually quite hard to catch.