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“Undetectable”: Your Burning Questions Answered

, by San Francisco AIDS Foundation

Dr. Joanna Eveland

Dr. Joanna Eveland (photo: Liz Highleyman)

Editor’s note (2016): Since this article was published in 2013, there have been many exciting developments in research on viral suppression and treatment as prevention. We now have substantial evidence that people living with HIV who maintain an undetectable viral load to not transmit HIV to sex partners. For an update on the science, read “Zero transmission with condomless anal sex and undetectable viral loads in PARNTER Study,” and “Raw sex: What the research says about risk when you’re undetectable.”

Last month, we asked for your burning questions about “undetectable” viral load. Thanks to everyone who posted a question! We enlisted Dr. Joanna Eveland of Mission Neighborhood Health Center to answer your questions about what “undetectable” means for your health and for your sex partners.

Can I still transmit HIV if my viral load is undetectable?

“Undetectable” and “HIV-negative” are not the same thing. Having undetectable viral load does dramatically decrease the odds of transmitting the virus, but it doesn’t eliminate it.

What does the science say? Watch this video to see how lower viral load translates to lower risk of passing on HIV.

Viral load is the amount of virus that is measured in the blood at one point in time. The test result you see at your doctor’s appointment today tells you what your viral load was a few weeks ago, when you got your blood drawn. If you continued taking your antiretroviral medicines daily, your viral load is probably still undetectable, but not necessarily.

Taking even a brief break from your meds can increase your viral load, as can having another illness like the flu or a sexually transmitted infection (STI). It’s also good to note that viral load in the blood is not necessarily the same as viral load in semen.

If I’m undetectable, do I still need to use condoms?

The decision to use condoms or not is ultimately between you and your partner. It’s important to discuss together what the health concerns might be for the two of you, and to be comfortable with your decision.

Things to think about and discuss with your partner(s) may include whether or not you have other sex partners, how frequently you get tested for other STIs, how adherent you are to your HIV meds, and how important (or not) using condoms is to you. Weighing the health concerns alongside the physical and emotional components will help you strike the right balance with your partner about “risks” and pleasure. While being undetectable is a great thing for your health, it doesn’t protect you against other STIs or offer an HIV-negative partner 100% protection against contracting HIV.

How can I tell if someone is undetectable?

You cannot “tell” if someone is undetectable just by looking at them; viral load is determined by tests that measure the amount of virus in a person’s blood. It’s just like how you can’t tell if someone is HIV positive.

If my viral load is undetectable, can I stop taking my meds?

No, you should NOT stop taking your meds. One of the main goals of taking HIV meds is to stop the virus from replicating (making more copies of itself) inside your body. If your viral load is undetectable, it means your HIV meds are working and you should definitely continue taking them. If you stop taking your meds, then HIV will resume its attack on your immune system and your health may worsen.

In the past, treatment interruptions or “drug holidays” were sometimes recommended because of concerns about medication toxicity, but HIV medications today are much safer and better tolerated. Also, we now know that untreated HIV is toxic to every system in the body, and that people who stay on continuous treatment (until we have a cure) have a lower risk of dying—not just from an HIV-related infection, but from a heart attack or cancer.

If the virus is undetectable in my blood, is it undetectable in my semen?

As you know, HIV can be found in both blood and semen. It’s important to remember that the amount of HIV in these bodily fluids differs. Research shows that HIV can sometimes be detected in semen even when viral load is undetectable in blood. Even if the viral load in your semen is at low levels, there may be chance that HIV can be transmitted to your partner. We do not yet know how much virus needs to be present in genital fluids for transmission to be possible.

Is it possible to become undetectable if I am not on HIV meds?

Most people have to take HIV meds to control the virus and become undetectable. About 1 in 300 people keep their viral load undetectable without taking medications. These individuals are called “elite controllers.”

Also, about 5% of HIV-positive people maintain healthy CD4 T-cell counts for at least ten years despite not having an undetectable viral load. People in this category are called “long term non-progressors.” We’re still learning what factors in a person’s immune system or in the virus lead to this phenomenon. It may be that some people’s immune systems are stronger at fighting the virus. It may be that the virus itself is weaker. If we understand how this works, we’re closer to a cure for HIV.

If I get an STI, can my viral load go up?

Yes, getting infected with an STI—or any other infection, like the flu—can cause an increase in your viral load.

If both my partner and I are undetectable, can we not use condoms?

If you’re both positive and want to stop using condoms, the research indicates that re-infection or super-infection is rare and the risk is greatly reduced for men who have longstanding (more than three years) HIV infection. For guys who got HIV more recently (less than three years), the research indicates that continued condom use may be a benefit.

Even if re-infection with HIV is not a concern, other STIs such as syphilis and gonorrhea can be. Having STIs can increase your viral load, not to mention that you can continue to re-infect your partner with an STI if you are not aware of it and don’t get treated. We’re also seeing more cases of hepatitis C being sexually transmitted, especially among HIV-positive gay men.

It’s important to talk with your partner about whether you have an “open relationship” and have sex with other partners. It’s also important to periodically revisit conversations about your sexual relationship. Some couples don’t revisit these conversations, only to find out that the original agreement may not have been maintained by both partners over time.

If I’m undetectable, does that mean I don’t have the virus anymore?

If you are undetectable, it means that the amount of HIV in your bloodstream is in low enough amounts that it is not detectable in your routine labs. It means you know your HIV status and are getting the HIV treatment and care you need to lead a healthy life. It does not mean that the virus has disappeared from your body.

The definition of undetectable has changed as our lab tests have gotten better. We used say someone was undetectable if they had less than a thousand copies of virus in a milliliter of blood. Today’s more sensitive tests can detect as low as 10–20 copies of virus in a sample.

Being undetectable isn’t a cure for HIV; current medications only go after HIV that is actively replicating, and some non-replicating virus hides inside our cells, unharmed by medications.

I heard that studies with straight couples showed that being on HIV meds reduced the chance of transmitting HIV by 92%–96%. Does this statistic hold true for gay couples, too?

Two studies compared HIV transmission in mostly heterosexual couples where the HIV-positive partner either started HIV treatment or delayed treatment; they found a 92%–96% reduction in HIV transmission risk when the HIV-positive partners started antiretroviral treatment.

These studies were done mostly with heterosexual couples; we’re not sure if the same findings apply to gay men, who may have different biological risk factors than straight couples (e.g., more anal sex vs. vaginal sex). Other factors, such as whether one or both partners has an STI, also affect the risk of HIV transmission.

Editor’s note (2016): Read “Zero transmission with condomless anal sex and undetectable viral loads in PARNTER Study” on BETA for an update related to men who have sex with men.

How long do I need to be on ART before my viral load becomes undetectable?

It depends primarily on what your viral load was before you started medications (more virus present means it takes more time to reduce viral load). Your T-cell count, general health, and whether you’ve been on treatment before also play a role.

The goal is that pretty much everybody should have an undetectable viral load after 16–24 weeks with appropriate treatment. If your viral load is not decreasing appropriately, your provider should check to make sure that you’re taking the medicines as directed, that you’re absorbing enough of them, and that you’re not resistant to them. Talking frankly about whether you’re taking the medicines, any bad side effects you have, and any other medicines, supplements, or recreational drugs you are using will help you get to undetectable faster.

Get an HIV pharmacist’s tried-and-true tips and strategies for getting to undetectable viral load—and staying there.

Once you achieve an undetectable viral load, you’ll still need to get blood tests at least every six months to make sure that the medicines continue to work and don’t have any negative effects on your body. This is an essential part of keeping your virus in check and staying healthy with HIV.


5 Responses to “Undetectable”: Your Burning Questions Answered

  1. kyle says:

    Which studies are you citing regarding the serodiscordant couples? Everything I’ve seen about the positive member has put the number closer to 60-80% reduced transmission to the negative member, NOT 90%+

    I believe OTHER studies where the NEGATIVE member of a serodiscordant couple was put on antivirals, and THOSE showed a much higher reduced transmission compared to negative individuals not – but the positive individual was on antivirals in all cases.

    • Steve says:

      Kyle more like 100% effective in stopping transmission!! The one transmission was from a cohort who should have never been allowed in the study because he was not yet undetectable!

      What does ‘extremely low risk’ mean?

      There was a 96% reduction in HIV transmission risk demonstrated in the HPTN 052 study,
      which can be considered as ‘extremely low risk’. Within the study partnerships, there was
      only one genotypically confirmed HIV transm
      ission from an HIV-infected participant on ART.
      In this case, an individual randomised to immediate ART had not yet achieved an
      undetectable viral load at the time of viral transmission.

  2. San Francisco AIDS Foundation says:

    Thanks for your question, Kyle. The two studies mentioned here are Partners in Prevention and HPTN 052, in which HIV transmission was reduced by 92% and 96%, respectively, in couples where the HIV-positive partner was on antiretroviral treatment. (The study findings are reported at http://www.nejm.org/doi/full/10.1056/NEJMoa1105243#t=article and http://www.thelancet.com/journals/lancet/article/PIIS0140-6736%2810%2960705-2/abstract). The HIV prevention method you’re describing, where an HIV-negative person takes antiretrovirals, is PrEP (pre-exposure prophylaxis). You can read more about PrEP at http://betablog.org/iprex-update-with-robert-grant and at PrEPfacts.org.

  3. Robert Seth Vorisek says:

    Even if you are undetectable, the still means there is free-floating virus in you blood. Yes, it’s lower than <20, meaning 20 copies/mL. But that also does not show what's beyond the blood/brain barrier. Until we can test – which we cannot now safely do, until you are dead, we may never know what is hiding quiescent in your brain, waiting to strike when you least expect it.

    • Steve says:

      20…. Are you really focusing on less than 20?… seriously? Do you know what the viral loads are during acute and early infection? and you are focused on less than 20… I can’t help but laugh at loud. How do you handle the risk of crosssing the street, taking a shower each day? Please find me 1 shred of evidence of any transmission at this level. Not a bunch of fluff please…we’re not sure…may be chance…viral load is probably… Can you guys just stick to the facts?