for Veterans and the Public
Frequently Asked Questions
Q: If taking anti-HIV drugs has made your viral load undetectable (meaning that the virus isn't showing up on blood tests), can you still pass the virus to another person through sex?
Taking anti-HIV drugs (ARVs) is very important for both your health and for reducing your risk of passing HIV to sex partners, but it is not 100% effective at preventing HIV transmission. A large international study looked at heterosexual couples in which one partner was HIV positive and the other was HIV negative. The researchers found that if the positive partners took HIV medications to suppress their viral load, their risk of infecting their partners was enormously reduced. In fact, the rate of HIV infection for the HIV negative partners was 96% lower if the positive partner was on ARVs. While we don't know for sure whether HIV medications will have this huge benefit in preventing HIV transmission between men who have sex with men, or between other types of partners, we think it will.
There's no way to know whether suppressing the HIV viral load through ARV therapy will be protective for you or for any specific individual. Keep in mind that a viral load test measures the amount of HIV virus in your blood. But sexual partners are usually infected by virus in sexual fluids, such as semen or vaginal or anal secretions. Unfortunately, the viral load in these fluids can be high even when the viral load in blood is low. And factors like STDs (sexually transmitted infections) can increase the risk of HIV transmission.
It is important to ask your health care provider for advice that is specific to you as an individual, and to your partner, in order to get a better idea of your risk for passing HIV and ways that you might lower this risk. And of course, it is really important to have frank and open conversations about HIV transmission with your HIV negative partner(s), so you and they can make informed decisions about what level of risk you are willing to accept.
Finally, remember that for ARV therapy to be effective it is crucial that you take your ARVs every day, as prescribed, in order to keep the HIV virus suppressed to undetectable levels. And, ARV therapy does not take the place of other risk-reduction strategies like condoms and behavioral changes--these are important not just for HIV reduction but also for STD prevention and pregnancy prevention.