How much protection is enough protection?

Dr. Margaret Lambert-Woolley

With tears spilling down her cheeks, she asked me, “How could this happen? It was only once; I was careful; I’m not promiscuous!” 

I’m asked this question many, many times each week after explaining an abnormal Pap smear has been caused by Human Papilloma Virus (HPV),  or after diagnosing what someone thinks is a “yeast infection” as actually being genital herpes, or after diagnosing a sore throat as actually a chlamydia infection or an HPV condyloma, and the list goes on . . .

My answer is simple . . . there is no such thing as “safe” sex.  You can do everything “right” . . . you can choose your partner carefully, you can limit the number of partners you have, you can use condoms 100% of the time, and you can still acquire a sexually transmitted infection.  Oral sex is not a “safe” alternative either.  You can acquire the same infections in the mouth and throat that you can acquire in the genital area. (ACOG practice bulletin # 582, December 2013 ) 

The real question is, how much can condoms help in protecting against transmission of STD’s?  In The New England Journal of Medicine (2006; 354, 2645-2654), the authors state “the protection that condoms provide against a specific sexually transmitted disease cannot be precisely quantified.” They cite difficulties with condom studies across the board regarding poor study design.  In 2000, Congress ordered the Secretary of Health and Human Services to examine this issue in detail, wondering if the labeling on condoms should be changed.  In reviewing the scientific literature on condoms, once again, they were struck by inconsistencies. Working as best they could with the studies they had to work with/analyze, they clarified the issue by dividing STDs into three categories:

1)            Those transmitted by sexual secretions—in this group, condoms would contain the man’s secretions, and the evidence suggested good protection from HIV and gonorrhea in men, for example, assuming no leakage.

2)            Those diseases transmitted by ulcers, like genital herpes (which could also at times be transmitted in fluids)—in this group, if the condom covered the lesion, protection could be good.  However, if the lesion was tiny, unnoticeable, and without symptoms, AND was on a part of the skin NOT covered by the condom, well, then . . . exposure to the female is much more likely.  Also, when you consider that 1 in 5 sexually-active adults has been exposed to genital herpes and can be a carrier and infect a partner WITHOUT symptoms (Leone, P. et al  Sex Trans Dis 2004; 31 (5) 311-316) . . . even sex with a condom is not necessarily “safe.” 

3)            HPV—this gets its own category, as all that is required is skin-to-skin contact (no fluids), and this virus is often shed from skin that is not covered by a condom.  Again, considering that at some “snapshot” in time, 80% or more of sexually active people will have HPV, we can see why this virus is spread far and wide.

How much protection is enough protection?  While the authors of the above-cited NEJM article conclude, “Six years later we have strong evidence that condoms reduce the risk of transmission of HIV, gonorrhea and chlamydia, [as well as] HSV in both men and women,” and recent studies suggest a decrease in the risk of HPV infection also, the question remains, decrease by how much?  And in the end, how much risk is acceptable?  Hence, the CDC’s recommendation for the ABC’s:

A – Abstinence

B – Be faithful

C – Condoms