Against HIV: 57-90%. For other STDs, from no risk reduction (for Chlamydia and Human Papilloma Virus) to 50-75% reduction (for gonorrhea).
Since the emphasis on “safer sex” practices is on using a condom, you should have a clear understanding as to how effective a condom is in preventing disease. First of all, in order to be effective at all, a condom must be worn every time, must have been properly stored, and must be properly used. In such cases of “perfect” use (did you know that this can only be achieved in a lab?), these are the statistics:
- Against the HIV virus, it is between 57% and 90% effective. [Some studies have found 57%, some 90%, and some a percentage in between.) But this is true only for penile-vaginal (i.e. heterosexual) sex. Heterosexually transmitted HIV represents only 0.03% of all annual cases of STDs.
- Against gonorrhea, “perfect” use of a condom prevents transmission of the disease 50-75% of the time, in men only. Most cases are not passed from female to male, and at any rate gonorrhea represents less than 2% of all cases of STDs.
- That means that for 98% of all STDs there is no proof that condoms reduce the risk of transmission. (Scientific Evidence on Condom effectiveness for Sexually Transmitted Disease Prevention,” July 2001)
This helps to explain why three of every four sexually active adults in the United States currently have, or have had, an HPV infection (which can cause infertility and premature deliveries, and which kills far more women than does AIDS) and why every year three million Americans (40% of whom are 15-19-years-olds) contract Chlamydia (a cause of cervical cancer and of persistent, year-after-year abdominal pain).