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Sex without a condom and HIV

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Condomless sex (vaginal or anal sex without a condom) is how the great majority of people become infected with HIV and other sexually transmitted infections (STIs) during sex.

How is HIV passed on during sex without a condom?

During sex without a condom, HIV moves from a body fluid of an infected person (blood, semen, vaginal fluids, pre-cum or anal mucus) into the body and bloodstream of their sexual partner. This happens via the delicate and absorbent mucous skin of:

  • the penis,
  • vagina,
  • lining of the rectum,
  • the mouth and throat (though it’s very rare to catch HIV this way).

How risky is it to have sex without a condom?

An infection doesn’t happen every time sex without a condom takes place, but it could happen any time it takes place.

A person can have unprotected sex with an infected person quite a few times and not get infected. But no-one should think they are immune to HIV or that they can carry on taking risks without becoming infected.

The more people you have condomless sex with, the greater the chance that one of them might have HIV and the greater the chance of you becoming infected.

Someone is much more likely to pass on HIV during the first few months after getting infected when he or she has very high levels of the virus in their body fluids. But during this period this person is unlikely to know they have HIV.

Someone who is on HIV treatment with an undetectable viral load has a low risk of passing on HIV.


What is the best protection against HIV and STIs?

Male and female condoms are good at stopping HIV, especially if used properly - eg, with water-based lubricant (oil-based lube weakens condoms).

If a man with HIV who isn’t on successful treatment ejaculates inside his partner, this raises the risk of infection.

Pulling out before ejaculation lowers the risk but this can be hard for men to control so shouldn’t be relied on.

Also, HIV is found in pre-cum - so even if a man manages to pull out before this happens, he could infect a partner with his pre-cum.


Are some types of sex more 'risky' than others?

  • Millions of men and women around the world have got HIV through vaginal sex.
  • Anal sex without a condom (sometimes called ‘barebacking’) has an even greater HIV risk. This is because the lining of the rectum is not as tough as that of the vagina, so it’s more likely to bleed during sex. This gives HIV in infected semen an easier way into a partner’s body.
  • Oral sex is low risk (but not no risk).

Is risk lower when the infected partner is on treatment?

Yes. If you are HIV positive and have an HIV negative partner, HIV treatment can also be used as a prevention method.

There’s an extremely low risk of you passing on HIV through sex, as long as:

  1. your viral load has been undetectable for the past six months
  2. you are on HIV treatment
  3. neither you nor your partner has an STI.

How do we know this?

A large study called PARTNER has been looking at over 1,000 gay and straight couples where one partner is HIV positive and one is HIV negative. The study won’t finish until 2017 but early results have shown that where the HIV positive partner had an undetectable viral load and was on treatment, there were no cases of HIV transmission whether they had anal or vaginal sex.

It’s important to remember that these are preliminary findings so as the study goes on the advice may change, but this is what has been reported so far.

If you have HIV, having untreated STIs could make it more likely that you’ll pass on HIV during condomless sex. But if HIV drugs have made your viral load undetectable then STIs don’t appear to make you more likely to pass on HIV.


Telling your partners about your HIV status

If you’re having safer sex (non-penetrative sex or sex with a condom) there’s no law saying you must tell people that you have HIV - it’s your choice whether you tell your sexual partners.

However, in England and Wales there’s a risk of being prosecuted for reckless transmission of HIV if:

  1. You had sex with someone who didn’t know you had HIV,
  2. you knew you had HIV at that time,
  3. you understood how HIV is transmitted,
  4. you had sex without a condom, and
  5. you transmitted HIV to that person.

The law in Scotland is largely the same, except that a case can also be brought if transmission hasn’t taken place but someone has been put at risk of transmission without their consent or knowledge.

Our pages on unprotected sex and the law and high-risk sex have further details.


More information:


Microbicides and PrEP ››

 

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The Information Standard: Certified member

This article was last reviewed on 17/5/2016 by Anna Peters

Date due for the next review: 17/5/2019

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