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Are condoms effective at preventing HIV and sexually transmitted infections (STIs)?
The evidence for the effectiveness of condoms is clearest in studies of couples in which one person is infected with HIV and the other not ( discordant couples). In a study of discordant couples in Europe, among 123 couples who reported consistently using condoms, none of the uninfected partners became infected. In contrast, among the 122 couples who used condoms inconsistently, 12 of the uninfected partners became infected. 2 A recent review of 14 studies involving discordant couples concluded that consistent use of condoms led to an 80% reduction in HIV incidence. 3 4
The male latex condom is the single, most efficient, available technology to reduce the sexual transmission of HIV and other sexually transmitted infections. 7
How often do condoms fail?
“The main reason that condoms sometimes fail is incorrect or inconsistent use, not the failure of the condom itself”
There is no one answer to this, as different studies have shown different results. Many studies of condom effectiveness have counted how often women have become pregnant when their partners have used condoms for birth control. This "failure rate" includes cases where the couple did not use a condom every time they had sex, or they did not use the condom correctly. Some studies have included the times the condom was torn accidentally by people using it. 8
The main reason that condoms sometimes fail to prevent HIV/STI infection or pregnancy is incorrect or inconsistent use, not the failure of the condom itself. Using oil-based lubricants can weaken the latex, causing the condom to break. Condoms can also be weakened by exposure to heat or sunlight or by age, or they can be torn by teeth or fingernails. Also, remember to check the expiry date of your condom!
How often do condoms break or slip off?
A large body of research in the United States has shown that rates of breakage, caused by fault in the condom itself, are less than 2 condoms out of every 100 condoms. Studies also indicate that condoms slip off the penis in about 1-5% of acts of vaginal intercourse and slip down (but not off) about 3-13% of the time. 9
Various studies have shown that knowledge and familiarity with the use of condoms reduce the likelihood of condom breakage and slippage during sex. 10 A major factor that can lead to a condom breaking or slipping off during sex is it's size, as this can affect how easy it is to put on and how likely it is to stay on. Different sizes of condoms are available, and it is important to make sure that the condom being used is the correct fit. 11
How are condoms tested?
Different countries have different regulatory agencies. In the United States, the Food and Drug Administration (FDA) regulates condoms to ensure their safety and effectiveness. Condoms in Europe that have been properly tested and approved should carry the CE Mark. Elsewhere in the world, you can find that condoms are approved by the International Organization for Standardization (ISO). Also, individual countries may have their own approval marks for condoms, for example, the Kitemark in the UK.
WHO guidelines set out a range of test requirements, which are necessary for ensuring the quality of each lot of condoms purchased. Based on international standards set out by the ISO, 12 these include tests which establish bursting volume and pressure, and detect holes and other visible defects. 13 Examples of the tests used by condom manufacturers include the 'water leak test', which reveals any holes in a condom, and the 'air burst test' or 'tensile test', which show whether a condom is likely to break during use.
- 1. CDC (2008) ' Male latex condoms and sexually transmitted infections', Fact sheet for public health personnel
- 2. De Vincenzi I. (1994) ' A longitudinal study of human immunodeficiency virus transmission by heterosexual partners', the New England Journal of Medicine; 331:341-346
- 3. Weller SC & Davis-Beaty K (2007), ' Condom effectiveness in reducing heterosexual HIV transmission'.
- 4. CDC (2008) ' Male latex condoms and sexually transmitted infections', Fact sheet for public health personnel
- 5. CDC (2008) ' Male latex condoms and sexually transmitted infections', Fact sheet for public health personnel
- 6. Holmes K. (2004, June), ' Effectiveness of condoms in preventing STIs' Bulletin of the World Health Organization 82(6).
- 7. UNAIDS, WHO and UNFPA (2009), ' Position Statement on Condoms and HIV Prevention'.
- 8. Sexuality Information and education Council of the United States (SIECUS) (2002) ' Fact Sheet: The truth about condoms', November
- 9. CDC (1999) 'Condoms and their use in preventing HIV infection and other STIs', September
- 10. National Institute of Allergy and Infectious infections, Department of Health and Human Services (2001, 20th July), ' Scientific Evidence on Condom Effectiveness for Sexually Transmitted Disease (STI) Prevention'.
- 11. UNAIDS (2001, May), ' The Male Latex Condom: 10 Condom Programming Fact Sheets'.
- 12. International Organization for Standardization, ' 4074: Natural latex rubber condoms - requirements and test methods'.
- 13. WHO (2010), ' The Male Latex Condom: Specification and Guidelines for Condom Procurement'.