Unprotected Sex

Unprotected sex is the term used to describe anal or vaginal sex if a condom is not used.
HIV and sexually transmitted diseases infections (STIs) can be passed on via by unprotected sex. Unprotected penetrative (the insertion of the penis into the body of another person) anal and vaginal sex carries the greatest risk of STIs, however, infections can also be transmitted through oral sex (mouth to genitals), and oral-anal sex (mouth to anus), also called 'rimming.'

Unprotected sex with HIV-negative and untested people

If you are HIV-positive, using condoms during sex with people who know that they are HIV-negative or are unsure of their HIV status will protect them against HIV and protect both of you from STIs.

There's a lot of debate about how infectious people with HIV are if they are taking HIV treatment and have an undetectable viral load. Most experts seem to agree HIV treatment means that the risk of HIV transmission is reduced, but that some risk still exists.

The law is also an important consideration. In the UK a number of people have been recently been sent to prison after infecting their sexual partners with HIV after failing to tell them they had HIV. You should also be aware that in some countries including you are legally required to disclose your HIV status to sexual partners.

Sex with other HIV-positive people

Many people with HIV have unprotected sex with their HIV-positive partners. Positive reasons for this include intimacy and pleasure

However, If you are HIV-positive and having sex with another person who is also HIV-positive, there are some important considerations that many HIV doctors and HIV prevention workers believe you should be aware of so you can make an informed decision about sex. These issues include:

  • There is a risk of pregnancy as a consequence of unprotected vaginal sex between men and women. There is a risk of transmission to the baby, when an HIV positive man has unprotected sex with an HIV negative woman who is pregnant or breast-feeding. However, with the right treatment and care, it's possible for an HIV-positive woman to have an HIV-negative baby.
  • There have been a small number of cases of so-called 'superinfection' with a new strain or strains of HIV, which may either be more aggressive than or resistant to anti-HIV drugs. This could lead to the failure of treatments that might otherwise have been effective. This applies to both men and women. But the number of recorded cases of superinfection is small. The cases have almost all involved people who were infected with HIV for less than four years and either were not on HIV treatment, or were taking a treatment break.
  • Unprotected sex puts you at risk of other sexually transmitted infections. This applies to both men and women.

Bacterial STIs, such as gonorrhoea, and chlamydia can be treated just as easily and successfully in most people with HIV as in people who are HIV-negative, provided that they are diagnosed and treated. Failure to get prompt treatment can lead to infertility and in some cases damage to the internal organs. Syphilis, particularly in people with a low CD4 cell count can be harder to diagnose and cure and can be more aggressive when the immune system is damaged.

There are also viral STIs. Genital herpes and genital warts are not curable, even in people who are HIV-negative. Although both these infections will respond to treatment, they can reoccur and can be harder to control if you have a very weak immune system. Genital herpes is linked to an increased risk of HIV transmission, especially when ulcers are present. Some strains of the virus which cause genital warts have been linked with the development of genital cervical and anal cancers.

The liver viruses hepatitis A and hepatitis B and (less easily) hepatitis C, can also be passed on sexually and can be more complicated in people with HIV. Hepatitis can cause liver damage which can limit HIV treatment options and make you very unwell in its own right.

There are vaccines for hepatitis A and B (but not C), which should be available at your HIV treatment centre. Gay men in particular are advised to be vaccinated against hepatitis A and B. After you have been vaccinated it is important to have your immunity to hepatitis A and B checked regularly, as the vaccines do not offer permanent protection. There's now good evidence that hepatitis C can be passed on sexually. Some HIV-positive gay men have been infected with hepatitis C after having unprotected sex, and 'rougher' sex such as fisting.

Some of the opportunistic infections which affect people with HIV can be passed on through sex. Kaposi's sarcoma is thought to be passed on sexually through a form of herpes virus. Both HIV-positive and negative people can be affected by gut infections such as Giardia, amoebas (small parasites which live in the gut and cause diarrhoea), cryptosporidium and microsporidium which can be passed on through oral-anal contact or any sexual activity which leads to contaminated faeces getting into the mouth. These infections can cause very severe diarrhoea which is particularly in people with very low CD4 cell counts.

Having an untreated STI increases the amount of HIV in the genital fluids, making HIV easier to pass on if you have unprotected sex.

It is recommended that all sexually active people have regular sexual health check-ups. Many HIV treatment centres have sexual health clinics attached, which in the UK offer free and confidential testing and treatment.
Now we have the proof that microbicides can work, what are the next steps toward providing one? How will they be provided and distributed? What might they cost? And how will they be marketed to people who would benefit?

Experts at a press conference and later panel discussion yesterday warned that the CAPRISA study result (see aidsmap report: Microbicides can work, CAPRISA trial shows, but more trials needed before approval) was only a first step and it would be at least three or four years, even if other studies also produced positive results, before a microbicide hit the clinic shelves, and possibly longer.

At the press conference, US HIV research chief Anthony Fauci, director of the National Institute of Allergies and Infectious Diseases (NIAID), said that the implications of the CAPRISA study were "really enormous" and that he had been impressed by the statistical robustness of the study. "However you slice it, this is a significant result," he said. "The first thing I will do when I get home will be to move microbicides from the column marked 'non-proven' into the 'proven' column.

"It fulfils an extraordinary need and is an opportunity for a group of people who've had very little opportunity to direct their own fate. Now they will."

Henry Gabelnick of CONRAD, the contraceptive research and development organisation that supplied the gel, said that the next step would be to approach both the Food and Drug Administration in the US and the South African Medicines Control Council and ask them what other trials would be necessary to satisfy them that microbicides worked.

One trial would be the only other microbicide efficacy trial currently underway, the VOICE study, which compares tenofovir gel (used daily rather than when having sex) with tenofovir (Viread) and Truvadapills as prevention methods. However, there remain gaps in our knowledge, and other studies would be needed - looking at use in adolescents, during pregnancy, and to see if it could work if applied after sex.

We also need to find out if it had any bi-directionality, i.e. does it protect men if HIV-positive women use it. But Catherine Hankins, chief scientific advisor to UNAIDS, warned that microbicides containing a single HIV drug should never be used by a person with HIV until we know a great deal more about whether it could cause resistance - though there was no sign of resistance in CAPRISA.

What about rectal use? Ian McGowan of the Microbicides Trials Network said that safety studies of rectal microbicides had already begun, and that ones featuring tenofovir or tenofovir plus the NNRTI drug UC781 were ongoing or planned. However, rectal microbicide development was a good five to six years behind vaginal microbicides.

Microbicides and circumcision could achieve modest cuts in HIV infections in Africa

Gus Cairns
Published: 22 July 2010

Three mathematical models presented at the Eighteenth International AIDS Conference in Vienna have found that circumcision and a microbicide, used separately or together, could produce modest reductions in HIV incidence.

The models, by Andrew Cox of the London School of Hygiene and Tropical Medicine and Hiam Chemaitelly of Weill Cornell Medical College in Qatar, broadly agreed that a realistic level of microbicide and circumcision adoption would produce an approximately 20% reduction in new HIV infections within 15 to 20 years. Adding comprehensive antiretroviral therapy (ART) into this mix would reduce new infections considerably more.

A third model, by Geoffrey Garnett of Imperial College in London, was cited by Bill Gates in his conference talk on Monday. This showed that adding in microbicides and pre-exposure prophylaxis (PrEP) to currently available prevention interventions - excluding ART - would reduce HIV infections by an additional 15 to 18%.

Andrew Cox's model used as its baseline the current situation in Uganda and forecast changes for the next 15 years.

He initially assumed a rise in the proportion of men in the population who were circumcised would rise from 18%, as it is now, to 48% over the next ten years, and then stay the same. He assumed that circumcision stopped six out of ten infections in men. For microbicides, he initially assumed an efficacy of 60% (rather on the high side for the microbicide in the CAPRISA study) , that women would use them 80% of the time when they had them, and that they would be available to 30% of the population after ten years.

Under these circumstances, circumcision (if provided alone) would produce a 12% decline in new infections in the whole population and microbicides alone an 8.4% reduction, but they would produce a nearly 20% reduction if used together.

Various combinations of microbicide and circumcision would produce a 20% reduction, but one combination cited by Cox was 53% circumcision coverage combined with 35% microbicide coverage - both higher than his initial assumptions. A 40% reduction in incidence would require probably unrealistic coverage rates of 81% for circumcision and 63% for microbicides, and a 30% reduction in incidence would require 68% coverage of circumcision and 46% coverage of microbicides use.

Inevitably, circumcision would benefit men more and microbicides would be of greater benefit to women. If circumcision was the only intervention used, 70% of the reduction in infections seen would be amongst men and if microbicides alone were used, 65% of the reduction would be in women, but if used together, the sexes would share the benefit equally.

Hiam Chemaitelly looked at the effect of circumcision in serodiscordant couples and weighed it up against the impact of treating the HIV-positive partner; treating the negative partner (as PrEP); and 100% condom use. Her model did not include microbicides as it was developed before the CAPRISA result came out, but she commented that a microbicide appeared about as effective as male circumcision.

She based her modelling on an existing cohort of 1003 serodiscordant couples who are enrolled in a study in the town of Bushenyi in south-west Uganda.

Amongst the parameters used in a complex model were: a circumcision efficacy of 58%; that, if supported by voluntary counselling and testing (VCT), condoms would be 80% effective and would be used 57% of the time; that PrEP would be 60% efficacious at stopping infections and that adherence to it would be 72.5%; and that antiretroviral treatment would be 92% efficacious and that adherence to it would be 80%.

Importantly, she assumed in her initial model that everyone who was eligible for a specific intervention would be offered it.

Under these circumstances, she found that antiretroviral therapy (ART) used alone would produce a 69% reduction in infections between the partners; condoms (with VCT) and PrEP would reduce new infections by 37%; and circumcision by 19%.

Greater efficacies would result from combining them, thus:

  • Condoms and ART, 82%
  • PrEP and ART, 82%
  • Circumcision and ART, 75%
  • Condoms and PrEP, 62%
  • Circumcision and PrEP, 50%
  • Circumcision and condoms, 49%.

Finally, if all four interventions were used together, the reduction in infections would be 92%.

Chemaitelly emphasised the importance of condoms being supported by VCT; if people used condoms without counselling and testing support, she found much lower rates of efficacy for them. Similarly, if the other three interventions were in short supply, reductions in infections would be much lower. Hr model also assumed universal provision of ART to the positive partner; if it was only provided to people with CD4s under 350 or 200, lower effectiveness rates resulted.

She pointed out that her model showed that there was no 'magic bullet' in prevention and that impressive reductions in the infection rate between couples was only achievable by using the range of interventions available in combination.


Cox A et al. Combination prevention to achieve significant reductions in HIV incidence: projections of the impact of microbicide and male circumcision interventions in rural Uganda. Eighteenth International AIDS Conference, Vienna, abstract WEAC0101, 2010.

Chemaitelly H et al. The impact of interventions on HIV transmission at the level of discordant partnerships. Eighteenth International AIDS Conference, Vienna, abstract WEAC0102, 2010.

Further information

Presentations and related abstracts by Andrew Cox and Hiam Chemaitelly are available on the official conference website.