Expert: Kristen Brannock, MPH - 11/11/2008

Question
QUESTION: It has been three weeks since I had unprotected vaginal intercourse with a woman whom I met via and internet dating site. I have not been with another woman in over 18 years and then I got stupid.

Due to extreme paranoia I had a full test done 3 days after the incident for all STD's and HIV. This was done via a urinalysis and blood work/CBC for the HIV. All results came back negative.

Now that it is three weeks later, I am still worried sick about my possible exposure.

What are my risks?



ANSWER: You already know that you are potentially at risk by having unprotected sex. It takes 1-3 months for the body to produce enough HIV antibodies to be detected by the ELISA so you need to test outside of that window period for an accurate result.

---------- FOLLOW-UP ----------

QUESTION: Thank you for the response. I do realize that I am at risk and will have the test redone at 1 month and then again at 3 months. My question in the grand scheme of things is how high is the potential risk from 1 incident of unprotected vaginal intercourse?

Answer
Unprotected anal sex carries more risk than unprotected vaginal sex which carries more risk than unprotected oral sex.

Risk depends on a variety of things- some of which we don't know (for example, how the virus is circulating in the other's body if they are positive, if they are taking medication to reduce viral load etc).

HIV does not flow uniformly throughout the body so while a person may contract HIV from having sex once with someone positive, another person may not. Having sex with someone positive does not mean the other person will definitely contract the virus.