With nearly 10 years passed since antiretrovirals brought undetectable viral load into the AIDS lexicon, HIVers are increasingly using the coveted health status as a cloak when it comes to making safer-sex decisions.
A study of San Francisco men who have sex with men found that 52% of HIV-positive guys will have a discussion 'at least half the time' about their viral load before agreeing on safer-sex rules with a sexual partner who is either HIV-negative or of an unknown serostatus.
This behavior stems from a belief that having a low viral load means there is little or no chance of infecting anyone else. Medical experts generally agree that the probability of infecting someone else drops significantly with a lower viral load. But they still say that rationalizing unsafe sex because of a reading on a lab report is nothing short of Russian roulette.
'The thing about probability is that when it happens to you, it is 100%,' cautions Gal Mayer, MD, associate medical director at Callen-Lorde Community Health Center in New York City. 'You might just be the unlucky one.'
And the chances of this bad luck might be higher than you think.
It is important to understand that a viral load test concerns only the level of the virus in the blood. So even if your virus is undetectable'meaning there are fewer than about 50 copies of HIV per milliliter of blood'semen can have a higher level. Medical research has various conclusions on the topic, but in general it has shown that there is a relatively strong correlation between the levels of HIV in the blood and in semen. (Due to difficulties obtaining proper samples of vaginal secretions, research about women is scant.) However, this correlation varies from person to person.
According to a 2000 study published in the Annals of Internal Medicine, after six months of antiretroviral therapy'despite a large drop in viral load'38% of the patients on a two-drug combination and 13% of those on three still had detectable levels of HIV in their semen.
Unfortunately, because there is no routine test to detect the amount of virus in semen, you cannot know about how infectious you might be when you make safer-sex decisions. Furthermore, if you have a sexually transmitted disease or a urethral inflammation, you may have an elevated viral load in your semen.
On this issue it is tempting to paint probability in terms of 'gray areas.' But it really is black-and-white: If you are infected, you can infect someone else.