Get tested and treated for other STDs and encourage your partners to do the same. All adults and adolescents from ages 13-64 should be tested at least once for HIV and high-risk groups get tested more often. STDs can have long-term health consequences. They can also increase your chance of getting HIV or transmitting it to others. It is important to have an honest and open talk with your healthcare provider and ask whether you should be tested for STDs. Your healthcare provider can offer you the best care if you discuss your sexual history openly. Find an HIV/STD testing site.
Choose less risky sexual behaviors. Oral sex is much less risky than anal or vaginal sex for HIV transmission. Anal sex is the highest-risk sexual activity for HIV transmission. If you are HIV-negative, insertive anal sex (topping) is less risky for getting HIV than receptive anal sex (bottoming). Sexual activities that do not involve the potential exchange of bodily fluids carry no risk for getting HIV (e.g., touching).
Use condoms consistently and correctly.
Reduce the number of people you have sex with. The number of sex partners you have affects your HIV risk. The more partners you have, the more likely you are to have a partner with HIV whose viral load is not suppressed or to have a sex partner with a sexually transmitted disease. Both of these factors can increase the risk of HIV transmission.
Talk to your doctor about pre-exposure prophylaxis (PrEP). CDC recommends that PrEP be considered for people who are HIIV-negative and at substancial risk for HIV. For sexual transmission, this includes HIIV-negative persons who are in an ongoing relationship with an HIV-positive partner. It also includes anyone who 1) is not in a mutually monogamous* relationship with a partner who recently tested HIV-negative, and 2) is a gay or bisexual man who has had anal sex without a condom or been diagnosed with an STD in the past 6 months; or heterosexual man or woman who does not regularly use condoms during sex with partners of unknown HIV status who are at substantial risk of HIV infection (e.g., people who inject drugs or have bisexual male partners). For people who inject drugs, this includes those who have injected illicit drugs in the past 6 months and who have shared injection equipment or been in drug treatment for injection drug use in the past 6 months. See more information at http://www.cdc.gov/hiv/basics/prep.html
Talk to your doctor right away (within 3 days) about post-exposure prophylaxis (PEP) if you have a possible exposure to HIV. An example of a possible exposure is if you have anal or vaginal sex without a condom with someone who is or may be HIV-positive, and you are HIV-negative and not taking PrEP. Your chance of exposure to HIV is lower if your HIV-positive partner is taking antiretroviral therapy (ART) consistently and correctly, especially if his/her viral load is undetectable (see Can I transmit HIV if I have an undetectable viral load). Starting medicine immediately (known as post-exposure prophylaxis, or PEP) and taking it daily for 4 weeks reduces your chance of getting HIV.
If your partner has HIV, encourage your partner to get into care and to take HIV medicine as prescribed. Taking HIV medicine as prescribed can make the level of virus in their body very low (called viral suppression) or even undetectable. A person with HIV who gets and stays virally suppressed or undetectable can stay healthy and has effectively no risk of transmitting HIV to HIV-negative partners through sex.

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