AIDS, gays, and blood donation – by the numbers

In the wake of the worst mass murder in American history – this time at a gay nightclub – many people are lining up to donate blood for the victims. In what may seem like a twist of irony, gays still face restrictions when it comes to donating blood.

Is this a legitimate form of discrimination (as I previously wrote about), or is this an unjust form of discrimination? Let’s look at some numbers.

According to this website, there are more than 1.2 million people in the USA living with the HIV infection, out of a total of about 320 million people in the USA. Furthermore, gay men, “accounted for 54% of all people living with HIV infection in 2011, the most recent year these data are available.”

54% of 1.2 million is about 650,000 – the total number of HIV positive people who are homosexual – and the rest (approximately 550,000) are not homosexual.

The total proportion of individuals in the USA who engage in homosexual activity is estimated to be around 3.8% of the adult population, or about 2.9% of the total population; roughly 9.3 million people. As an approximate number, then, the total who don’t participate in homosexual activity is the remainder, or just over of 310 million people.

So if I’m part of the blood donor group and a straight person comes up to me and says they’d like to donate blood, the million dollar question is, “what are the odds this straight person is currently infected with HIV / AIDS?” Based on the above numbers:

550,000 / 310,700,000 = 0.0018 = 0.18%

Less than a fraction of a percent of the non-homosexual community is infected with HIV / AIDS, so the odds that this individual who would like to donate blood is infected is about 1 in 558.

Let’s take that same thought experiment, but now the person who would like to donate blood is homosexual. Same question, “what are the odds this homosexual person is currently infected with HIV / AIDS?” Again, based on the above numbers:

650,000 / 9,300,000 = 0.069 = 6.9%

Within the homosexual community, approximately 7% are currently infected with HIV / AIDS; about 1 in 14.

That’s about 30 times higher than the non-homosexual communityThis paper claims, “HIV and early syphilis rates among MSM are >40 times higher than those among heterosexuals.” And this resource gives very similar numbers to what I calculated; roughly 34 times more likely among homosexuals, and the prevalence of HIV / AIDS is just over 7% of homosexuals.

The math doesn’t lie: the likelihood that a homosexual person has HIV / AIDS is vastly higher than the likelihood that a non-homosexual person has HIV / AIDS. And when we’re dealing with blood donation that’s kind of a really big deal.

Some people will point out that the blood donor organizations screen the blood before using it, so we shouldn’t restrict all the healthy homosexuals from donating just because some homosexuals are infected. The problem with this idea is that no screening process is 100% accurate. If the screening were 100% accurate then I think a case could be made to let anybody and everybody donate blood, but that isn’t possible at this point in history. As long as we are dealing with the real world where the accuracy is something less than 100%, then we would be wise to reduce the risk of tainted blood getting past the screening process by restricting blood donors to those demographics in the general population who are far less likely to have tainted blood in the first place; non-homosexuals.

How well would that conversation go with one of the survivors of the Orlando attack?

“Hey, congratulations on surviving the single worst gun massacre in American history. So, um, this is a little awkward. Some of the blood that we used to keep you alive was unfortunately tainted with HIV / AIDS. Although the bullets didn’t kill you, our concern for not offending people unfortunately will kill you in a few years. Sorry about that.”