fmota

In response to this survey that finds that 75% of gay and bisexual men would be willing to donate blood, and to countless reddit commenters who, even on the lgbt subreddit, insist that the ban on blood donations from men who have had sex with men since 1970 is rational, I crafted the response below. I hope to convince you that this ban is irrational and hurtful.

(Note: this was originally a comment on the reddit submission of the aforementioned survey.)

Let’s use math.

Let p be the portion of the population that has AIDS.
Let h be the portion of the population that is homosexual men.
Let m be the portion of the population that is willing to donate blood.

Case 1: If we allow everyone to donate (i.e. without discrimination against men who have had any kind of sex with a man since 1970), then the probability that a blood donation is contaminated with HIV is p (assuming that HIV+ people are just as likely to donate blood as HIV- people, which is not true). Also, the portion of the population that can donate blood is m.

Case 2: If we ban sexually active gay/bisexual men from donating blood, then the probability that a blood donation is contaminated with HIV is p(1 - 0.5h) (assuming roughly 50% of AIDS cases come from homosexual men. Also, the portion of the population that can donate blood is m - 0.75h (assuming roughly 75% of gay men would donate blood, as this survey suggests).

---

Now that some of the math is out of the way, let’s plug in some statistics.

http://www.cdc.gov/hiv/topics/surveillance/basic.htm#aidscases:

At the end of 2006, an estimated 1,106,400 persons (95% confidence interval 1,056,400-1,156,400) in the United States were living with HIV infection, with 21% undiagnosed.

Google tells me that the population of the U.S. is 304,059,724. So, 1,106,400 / 304,059,724 is approximately 0.0036. This is p.

The percentage of homosexuals in the population has been variously estimated as between 3 to 13 percent, so let’s say 7 percent is gay. The percentage of homosexual men, then, is 3.5 percent. That is, 0.035 of the population. This is h.

http://www.americasblood.org/go.cfm?do=page.view&pid=12:

Only 38 percent of the U.S. population is eligible to donate blood – less than 10 percent do annually.

This 10 percent figure is of course only out of eligible donors. If gay men were eligible, this 10 percent figure would be higher by 0.75h (if we assume that every gay men that would claim in this survey that they would be willing to donate blood, would do so at least once a year, which isn’t going to be the case, but I don’t see how we can get around this slight but unfortunate inaccuracy).

So let m = 0.1 + 0.75h = 0.1 + 0.026 = 0.126

In summary,
p = 0.0036
h = 0.035
m = 0.126
population of the US = 304,059,724

---

Let us now look at the cases above with our numbers.

Case 1: If we were to allow everyone to donate, then the probability that a blood donation is contaminated with HIV is p = 0.0036. Also, the portion of the population that can donate blood is m = 0.126. In real numbers, this means that 38,300,000 people donate blood every year, and of those donors, 137,880 are contaminated with HIV.

Case 2: If we ban gay/bisexual men from donating, then the probability that a blood donation is contaminated with HIV is p(1 - 0.5h) = 0.0036(1 - 0.035) = 0.0036 * 0.965 = 0.00347. The portion of the population that donates blood every year is 0.1 (i.e., the statistic above). In real numbers, this means that 30,400,000 people donate blood every year, and of those donors, 105,510 are contaminated with HIV.

Comparing the two cases, we can see that in Case 1, an additional 7,900,000 people are willing to donate blood at least every year than in Case 2. We also see an increase of 32,370 in the numver of donors who have HIV in Case 1 over Case 2. This corresponds to an increase of 0.00013 HIV-likeliness per donor (i.e. an increase of 0.013%.)

So the question, ultimately, is whether a 0.013% increase in the likeliness of HIV-contaminated donations justifies discriminating against gay/bisexual men, who could otherwise constitute 7,870,000 HIV-free donors (and 32,270 HIV+ donors).

Note that an increase in HIV+ donors will correspond to a much smaller increase in HIV+ blood transfusions, for two reasons: 1. Most HIV+ people know they are HIV+, and would therefore be excluded from donation anyway. 2. Blood donations get screened. If they find anything wrong with the blood, they simply throw it away. You can bet that they test every single blood donation for HIV/AIDS.

(Side note: if you object to my point no.1 in the preceding paragraph, by saying that some HIV+ gay man would want to maliciously donate blood, and therefore lie, I have to ask you: what is stopping said person from donating blood now? Would a lying scumbag not also lie about their past sexual encounters? (This argument is just a pet peeve of mine.))

In closing, I hope to have convinced you that banning blood donations from men who have had sex with men since 1970 is a discriminatory policy, rooted more in homophobia than in fact. It’s a policy that harms both those in need of blood, and the psyche of gay/bisexual men.