The goal of HIV prevention is to help people learn how to eliminate or reduce their risk of becoming infected with HIV or of transmitting HIV to others.

HIV prevention takes place at two levels - the primary prevention and secondary prevention.

Primary HIV prevention focuses on keeping people from becoming infected with HIV and on helping people who are HIV-positive to help individuals develop skills for reducing the risk of infecting others.
Secondary HIV prevention focuses on helping prevent HIV-positive people from developing opportunistic infections, preventing the infection from progressing to AIDS and preventing HIV transmission to others.

Abstinence from sexual relations is the surest way to prevent the sexual spread of   STDs like   HIV.
Get tested and share your STD status with your partner before having sex. Then   practice   safer sex techniques to prevent infection.
Use a new latex barrier (a male condom, female condom, or dental dam) at each   vaginal,   anal, or oral sex encounter.
Use a water-based lubricant with condoms. Do not use baby oil or other   oil-  based lubricants   such as Vaseline. These may cause holes to form in the   condom, causing it to break.
Products containing the spermicide nonoxynol-9 (found in most contraceptive   creams, gels,   suppositories, foams, films and sponges) help to prevent   pregnancy but may increase the risk   of HIV.
Never share sex toys.
Engaging in a committed, monogamous relationship with a person who is free   from HIV or   any other STD is safer if you both mutually agree to refrain from any   high-risk behaviors.
Be aware of cultural and social norms that may weaken your ability to negotiate   with sex   partners for safer sex.

Tell anyone you're going to have sex with that you have HIV.
If you have sex, use a new latex condom or other latex barrier every time, even if   your   partner is also HIV-positive.
Don't share needles or drug works.
Tell anyone you've had sex with that you have HIV.
Don't donate blood, plasma or organs.
Don't share toothbrushes or razors.

Get tested and seek treatment for HIV before becoming pregnant or as early as   possible during the pregnancy.
Take zidovudine (AZT or ZDV) or nevirapine during pregnancy and labor to   reduce the chance of transmission to your baby.
If you are HIV-positive, use baby formulas if they are available, since HIV can be   transmitted through breast milk.
Delivery by Cesarean section can reduce HIV transmission from a mother to her   baby.

Female-to-female sexual contact is a possible way to become infected with HIV,   although little research has been conducted in this area.
Oral or vaginal exposure to vaginal secretions and menstrual blood are   potentially infectious.

Use a new latex condom for each act of sex.
Women who have sex with men must rely on their own skills and knowledge   regarding condom use and their ability to convince their partners to use   condoms.
Both partners have a responsibility to have protected sex.

Always use new sterile equipment and supplies. Don't share or reuse any   piercing, tattooing, or injection needles.
Using needles cleaned with bleach or that have been heated is not as safe as   using new, sterile needles.
Don't share drug supplies. Make sure cotton, water, and the drug itself are not   contaminated.
If you are an injection drug user, seek treatment as soon as possible for your   substance abuse.
Don't share toothbrushes, floss, or razors.
If you are HIV-positive, don't donate blood, plasma or organs.
Try not to come in contact with other people's blood.