Today I had sex with a massage parlor sex worker. We used a condom and I last for about 2 minutes. I didn't ejaculate in her and the condom didn't break. Should I be worried about contracting HIV? Should I consider PEP? Im know my risk is zero and Im overreacting but I could use a second opinion.

I went to my primary care doctor and he advised again pep and further testing given the low to zero risk scenario. Is he right?

Information about the effectiveness of condoms can be confusing. Many online and other resources quote figures like 90% effectiveness. However, that kind of figure typically is the average effectivenss over time, taking into account condom breakage, improper use, forgetfulness, and so on. In other words, people who say they use condoms for contraception or STD/HIV prevention have only 90% effectiveness. (Scientifically, this is called "use effectiveness.") Howver, a properly used condom that does not break, does not slip off during sex, etc is much more effective. (This is called "biological effctiveness".) This is close to 100% for those infections transmitted through body fluids, such as gonorrhea, chlamydia and HIV. However, it's a bit less -- maybe 95-98%? -- for STDs transmitted by skin contact, such as herpes, syphiliis and HPV. If you think about it, this makes sense -- because even with proper use and no breakage, there often is skin contact above the condom.

In addition to using a condom, this was low risk for HIV anyway. In the US and other industrialized countries, well under 1% of female sex workers have HIV. And when a woman has HIV, the chance her male partner will catch it during unprotected vaginal is once for every 1,000 or more vaginal sex events. So the odds you would have caught HIV, even without a condom, were under one chance in many thousand, probably under one in a million. That's too low a risk for PEP.

Some men in your situation still get tested for HIV, however. It's up to you:  if you'll gain additional reassurance from a negative HIV test result, feel free to do it.

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD