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Semen and vaginal fluid

Several spermatozoa

If someone with HIV has a detectable viral load, their semen or vaginal fluid can contain the virus. If these fluids get inside a partner’s body during sex, the partner can get HIV.

Someone who is taking effective HIV medication and has an undetectable viral load cannot pass on HIV.


How do you get HIV from semen or vaginal fluid?

If a man has HIV, one of his body fluids where the virus is found is his semen.

If he has a detectable viral load and his semen gets into the body of his sexual partner during sex, then HIV can get into the other person’s bloodstream and infect them.

Pre-cum contains HIV - this is why there remains a risk of infection even if, during sex, a man pulls out of his partner before he ejaculates.

If a woman has HIV and she has a detectable viral load, one of her body fluids where the virus is found is in her vaginal secretions.

If these come into contact with a man’s penis during sex, then HIV could be transmitted to him - the virus in her secretions can enter through the delicate skin of his penis or foreskin.


Do condoms stop HIV being passed on?

Yes. This is called protected sex. Using a condom correctly prevents contact with semen or vaginal secretions (and blood), stopping HIV from being passed on from someone with a detectable viral load. The virus cannot pass through the latex of the condom.

Condoms should be used with water-based lubricant as oil-based lube weakens them.


HIV treatment is also a form of protection.

How HIV treatment stops HIV being passed on:

  1. A person with HIV who is taking treatment and has an undetectable viral load cannot pass on HIV. It can take up to six months on treatment for some people to become undetectable.
  2. Pre-exposure prophylaxis (PrEP) is a course of HIV drugs taken by an HIV negative person to lower the chance of infection. When taken correctly, PrEP significantly reduces the chances of becoming HIV positive.
  3. Post-exposure prophylaxis (PEP) is a month-long course of HIV medication taken by an HIV negative person after possible exposure to reduce the chance of getting HIV. When started in time, PEP can stop HIV infection after sex without a condom (or other exposure) with someone who is infectious - but it does not work every time.

The PARTNER study results

A large study called PARTNER looked at 888 gay and straight couples (and 58,000 sex acts) where one partner was HIV positive and one was HIV negative. Results found that where the HIV positive partner was on effective treatment and had an undetectable viral load, there were no cases of HIV transmission whether they had anal or vaginal sex without a condom.

The PARTNER study looked at couples where the HIV positive partner had a viral load below 200. An undetectable viral load is classed as being below 50 (although some tests can now measure below 20).

However, before deciding to stop using condoms, it’s a good idea to speak to your HIV doctor or nurse to make sure your viral load is undetectable.

It’s also important to remember that if you have sex without a condom other sexually transmitted infections (STIs) can be passed on.

Sex without a condom can also result in an unplanned pregnancy if other contraception is not being used.


HIV transmission through infected blood ››

‹‹ Back to: Modes of HIV transmission

 

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The Information Standard: Certified member

This article was last reviewed on 31/1/2017 by Anna Peters

Date due for the next review: 2/3/2020

Content Author: R. Scholey

Current Owner: Health promotion

More information:

HIV Transmission Risk Persists During the First 6 Months of Antiretroviral Therapy, Mujugira A1, Celum C, Coombs RW, Campbell JD, Ndase P, Ronald A, Were E, Bukusi EA, Mugo N, Kiarie J, Baeten JM; Partners PrEP Study Team
National Center for Biotechnology Information
US National Library of Medicine
2016 Aug 15;72(5):579-84. doi: 10.1097/QAI.0000000000001019

HIV treatment as prevention and HPTN 052, Cohen MS1, McCauley M, Gamble TR
National Center for Boiotechnology Information
US National Library of Medicine

No one with an undetectable viral load, gay or heterosexual, transmits HIV in the first two years of PARTNER study, Gus Cairns, NAM aidsmap, March 2014

Viral load and transmission, a factsheet for people with HIV, Gus Cairns, NAM aidsmap, September 2015

Viral load and transmission, a factsheet for HIV negative people, Gus Cairns, NAM aidsmap, September 2015

NAM, Semen, Aidsmap, (2012)

Gus Cairns, Many men With undetectable HIV in their blood still have low levels in their semen, studies find. NAM, Aidsmap (2012)

NAM, Withdrawal and the risk from pre-cum, Aidsmap (2012)

NAM, Viral load in semen, vaginal fluid and rectal secretions, Aidsmap, (2012)  

BHIVA and EAGA, Position statement on the use of antiretroviral therapy to reduce HIV transmission (September 2013)

Gus Cairns. No HIV transmissions from HIV-positive partner seen in Australian gay couples study, Aidsmap (2015).

Gus Cairns. No-one with an undetectable viral load, gay or heterosexual, transmits HIV in first two years of PARTNER study, Aidsmap (2014)

NHS Choices, HIV and AIDS 2014

Sexual Activity Without Condoms and Risk of HIV Transmission in Serodifferent Couples When the HIV-Positive Partner Is Using Suppressive Antiretroviral Therapy, Journal of the American Medical Association: Alison J. Rodger, MD; Valentina Cambiano, PhD; Tina Bruun, RN; Pietro Vernazza, MD; Simon Collins; Jan van Lunzen, PhD; Giulio Maria Corbelli; Vicente Estrada, MD; Anna Maria Geretti, MD; Apostolos Beloukas, PhD; David Asboe, FRCP; Pompeyo Viciana, MD1; Félix Gutiérrez, MD; Bonaventura Clotet, PhD; Christian Pradier, MD; Jan Gerstoft, MD; Rainer Weber, MD; Katarina Westling, MD; Gilles Wandeler, MD; Jan M. Prins, PhD; Armin Rieger, MD; Marcel Stoeckle, MD; Tim Kümmerle, PhD; Teresa Bini, MD; Adriana Ammassari, MD; Richard Gilson, MD; Ivanka Krznaric, PhD; Matti Ristola, PhD; Robert Zangerle, MD; Pia Handberg, RN; Antonio Antela, PhD; Sris Allan, FRCP; Andrew N. Phillips, PhD; Jens Lundgren, MD
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Viral load, Michael Carter, Greta Hughson, NAM, Aidsmap, March 2014

More confidence on zero risk: still no transmissions seen from people with an undetectable viral load in PARTNER study, Gus Cairns, NAM, Aidsmap, July 2016

Open your eyes to STIs, NHS Choices, Nov 2015

When sex goes wrong, NHS Choices, Nov 2015

Pre exposure prophylaxis, Roger Pebody, NAM, Aidsmap, October 2016

Can post exposure prophylaxis (PEP) stop me getting HIV, NHS Choices, Sept 2015

Can't pass it on

People on effective treatment can't pass on HIV

If everyone knew this, we could bring an end to stigma and stop HIV transmissions.

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