Consistent condom use in anal sex stops 70% of HIV infections, study finds
An analysis by Dawn Smith of the US Centers for Disease Control (CDC) reported at the 20th Conference on Retroviruses and Opportunistic Infections (CROI 2013) on 4 March has provided the first estimate of the efficacy of condoms in preventing HIV transmission during anal sex since 1989. It found condoms stop seven out of ten anal transmissions – the same efficacy found by the 1989 study. However, it also found that sometimes using condoms is not effective at preventing HIV infection, and that long-term 100% condom use is a minority behaviour: only one-in-six gay men actually managed to maintain it over the three- to four-year time frame of the analysis.
“This analysis also shows that sometimes using condoms is no better than not using them at all. Overall, men who said they sometimes used condoms were only 4.4% less likely to acquire HIV than men who never used them. This difference was statistically insignificant;”
Smith D et al. Condom efficacy by consistency of use among MSM: US. 20th Conference on Retroviruses and Opportunistic Infections, Atlanta, abstract 32, 2013.
There must be some other variables that aren’t being taken into account. Since all else being equal, using condoms some of the time should mean fewer episodes of unprotected sex should mean fewer chances to get infected.