position Probabilities
Written by Robert Bolan; David Rosenberg | Tuesday, 01 November 2011
Tags: health, instinct, november 2011, hiv/aids, weight loss, cosmetic procedures
Q: What is thought to be the risk—nowadays—for contracting HIV from topping?
Ben in Maine
A: I can’t give you an exact answer, but I can help you understand the relative risks involved in various exposures. There are three factors to consider, only one of which is affected by which position you’re in: Dose—How much virus is present in various locations in your HIV-positive partner during sex. A person not on treatment and with a very high serum viral load is going to have a lot of virus at different sites. We don’t actually measure viral load at different sites but use the serum viral load to tell us what the relative amount will be in, say, the rectal tissues. It will be higher in someone not on treatment (and maybe not even aware that they are positive), and it will be lower in someone on treatment. Exposure—This refers to how much surface area of mucous membranes (where the virus can enter the body) is exposed and to amount of time you are exposed. Since the opening of the urethra is relatively small, being a top entails less exposure than being a bottom. Resistance—This refers to your own resistance to HIV at the mucous membrane location of exposure. If you have an STD, for example (which you might not even realize), your body’s resistance to HIV is reduced. All other things being equal—the length of a sexual encounter, whether your immune system is compromised by another infection—your risk is considerably greater as a bottom than as a top. However, reduced risk is not the same thing as no risk. Unfortunately, we have seen many men test positive for HIV after unprotected sex; they often incorrectly assumed they did not need to use condoms if they only had sex as a top. I applaud you for wanting to be aware of risk factors in order to make educated decisions about your health. Please protect yourself, and get tested regularly, regardless of whether you are a top, a bottom or you switch it up. —RB