The real problem with male condoms is nonuse.

Abstract

WHEN USED CORRECTLY and consistently, male latex condoms are the most effective method to reduce the risk of sexually transmitted disease (STD)/human immunodeficiency virus (HIV) transmission during sexual intercourse.1,2 Rigorous prospective studies of HIV transmission among discordant couples provide compelling evidence that male latex condoms are highly effective only when used during every act of intercourse.3–5 But even then they are not perfect. Two of these serodiscordant studies4,5 and other prospective studies6,7 have documented transmission of HIV or STD during self-reported consistent use of male latex condoms (hereafter referred to simply as condoms). The article by Macaluso et al. in this issue of Sexually Transmitted Diseases suggests that condom breakage and slippage may be one cause of the observed failure of condoms to prevent STD/HIV transmission.8 In this large prospective study of high-risk patients in STD clinics, condoms broke or slipped off in approximately 4% of coital acts. These findings are consistent with the most recent review of prospective studies that presented a range of breakage during vaginal intercourse from 0% to 6.7% (with most study rates <2%) and a range of complete slippage from 0.6% to 5.4%.2 Recent studies have documented that a minority of users are responsible for a disproportionate amount of breakage and slippage.9–13 As a result, for most condom users, breakage and slippage is a more infrequent event than the above average figures would suggest. Moreover, many condom breaks and slips do not place the user at risk of transmission because they occur before intercourse or during removal (nonclinical breakage and slippage).14 Most importantly, condom users who report more frequent condom breakage and slippage can be counseled to develop skills to avoid behaviors that may be placing them at increased risk.13 In addition to condom breakage and slippage, a possible explanation for the observed failure of condoms to protect against STD/HIV transmission despite self-reported consistent condom use is that respondents did not provide valid information about their consistency of use. In other words, they did not consistently use condoms even though they reported doing so. A recent study finding no association between self-reported condom use and overall incident STDs7 was debated in Sexually Transmitted Diseases.15–18 The most recent analysis of the original data concluded that the primary reason for the lack of an association between self-reported consistent condom use and incident STDs was the fallibility of the self-report.19 A randomized controlled trial that empirically assessed the association between prevalent HIV in female sex workers and different methods of measuring condom use found little or no relationship between level of self-reported condom use and HIV prevalence.20 All condom-use measures were most strongly associated with infection when limited to intercourse with partners who were not clients. Much research still remains to be done on how best to elicit accurate responses about condom use through improved data collection instruments. The use of biomarkers such as prostate specific antigen (PSA) to detect evidence of semen in the vagina shows promise in making condom effectiveness trials less reliant on self-reported behavior.21 A second alternative explanation for documented cases of STD/HIV transmission during self-reported consistent condom use is that respondents did not use condoms during the entire act of intercourse. This behavior has been associated with gonorrhea transmission in at least one study.22 In one recent cross-sectional study of 47 university students, participants reported that 6% of acts resulted in breakage or slippage, while 10% were not protected with condoms throughout vaginal intercourse (put on after intercourse had started or removed during intercourse).23 A third, but highly unlikely, explanation for the documented cases of STD/HIV transmission during self-reported consistent condom use is the transmission of pathogens through microscopic holes in the latex. Two laboratory studies tested the permeability of latex condoms and documented minute amounts of HIV-sized particles passing through some of the latex condoms tested.24,25 Fortunately, the small amount of ejaculate estimated to pass through the latex would most likely be virus-free in a man infected with HIV, and the authors calculated the risk of HIV transmission to be reduced 10,000-fold with the use of condoms.24 This transmission risk may increase further with the improved quality of currently manufactured condoms.26 The types of condom and user failure we discussed earlier contribute disproportionately to the overall risk of STD/HIV transmission (Fig. 1). To create this figure, we used four imprecise assumptions: 1) 7.5 billion condoms used annually worldwide,27 2) 16.5 billion additional at-risk acts not protected by condoms annually worldwide,27 3) 10% of condoms no