Abstain from anal, vaginal or oral sex
The surest way to avoid the sexual transmission of HIV infection is to abstain from sexual activity with other people. The next surest way is to have sex with only one partner who is known to be uninfected with HIV AND who only has sex with you.

For someone with an HIV positive partner, a partner who does not know their HIV status, or multiple sexual partners, touching, dry kissing, body rubbing, and mutual masturbation are the safest sexual activities. For any penetrative sex acts such as vaginal, anal, or oral sex, condoms are highly effective at reducing the risk of HIV transmission especially when used consistently and correctly.

For those with a new sex partner, abstain or use condoms for at least 3 months and then get tested for HIV antibodies. If you and your partner are both HIV negative and each of you are not engaging in other risk behaviors (e.g., sharing needles or having other sex partners), then you won't have to worry about HIV infection.

Abstain from injection drug use
The surest way to completely avoid HIV infection from injection drug use is to abstain. The next surest way is to use a brand new syringe every time you inject. If brand new syringes are not available, properly bleaching a used syringe may be an effective method of reducing HIV transmission.

Sharing drug injection equipment (such as cookers, cottons and water used for mixing/bleaching) also can transmit HIV. To avoid infection, these items must not be shared. Public Health-Seattle & King County operates Needle Exchange Programs in several locations. Needle Exchanges trade new needles/syringes for used ones free of charge.

Drugs -- injected or not -- can also increase a person's risk for HIV by impairing judgement, decision-making ability, and/or by increasing sexual drive. Studies have shown that - even when drunk or high - people can successfully use condoms and clean needles/syringes. Nonetheless, people who are drunk or high often take more risks than if they were sober.