Sexual transmission

Sexual transmission

What works?

Someone can eliminate or reduce their risk of becoming infected with HIV during sex by choosing to:

• Abstain from sex or delay first sex
• Be faithful to one partner or have fewer partners
• Condomise, which means using male or female condoms consistently and correctly

There are a number of effective ways to encourage people to adopt safer sexual behaviour, including media campaigns, social marketing, peer education and small group counselling. These activities should be carefully tailored to the needs and circumstances of the people they intend to help.^{12 13 14}

Comprehensive sex education for young people is an essential part of HIV prevention. This should include training in life skills such as negotiating healthy sexual relationships, as well as accurate and explicit information about how to practise safer sex. Studies have shown that this kind of comprehensive sex education is more effective at preventing sexually transmitted infections than education that focuses solely on teaching abstinence until marriage.^{15 16}

A condom vending machine in Vatican City

Numerous studies have shown that condoms, if used consistently and correctly, are highly effective at preventing HIV infection.¹⁷ Also there is no evidence that promoting condoms leads to increased sexual activity among young people. Therefore condoms should be made readily and consistently available to all those who need them.¹⁸

There is now very strong evidence that male circumcision reduces the risk of HIV transmission from women to men by around 50%, which is enough to justify its promotion as an HIV prevention measure in some high-prevalence areas.¹⁹ However, studies of circumcision and HIV suggest that the procedure does not reduce the likelihood of male-to-female transmission, and the effect on male-to-male transmission is unknown.²⁰

Some sexually transmitted infections - most notably genital herpes - have been found to facilitate HIV transmission during sex. Treating these other infections may therefore contribute to HIV prevention.^{21 22} Trials in which HIV-negative people were given daily treatment to suppress genital herpes have found no reduction in the rate at which they become infected with HIV. Nevertheless, there is evidence to suggest that treating genital herpes in HIV positive people may reduce the risk of them transmitting HIV to their partners. Further research is ongoing.²³