Sunday, 17 April 2011

NHS homophobic? No, it's all about risk.

I was prompted to write this by an exchange on Facebook that contained several misleading statements about why the National Blood Service won't accept blood from homosexual men (Oh no, someone is wrong on the internet!). It started with the status update:
Fucking van drove by "NHS: Please Give Blood"
If you'd fucking take it, maybe I would, you bigoted, closed-minded twatheads!
This on its own wouldn't have prompted a blog post, I can appreciate the frustration that must be felt by someone who wants to perform what they perceive to be civic duty but are denied the opportunity for what seems, to them, like unfair reasons. I may disagree that they are unfair reasons, but can understand the frustration.
Before I start with what annoyed me about the subsequent discussion, let me declare a bias; this is a somewhat emotive topic for me having watched my brother and his life-partner and suffer an array of illnesses for years and then die a slow lingering death from AIDS related illnesses in the early nineties. While the excellent staff at the The Sussex Beacon cared for John in his final months, I was told several anecdotes about homosexual behaviours that were leading to the spread of HIV. I won't relate them here as they are just that, anecdotes, and therefore only peripherally useful in any discussion about how HIV is transmitted. Plus they are twenty years out of date, and you have to hope that if the stories I was told (by gay people) of repeated acts of unprotected anal sex with random partners of unknown sexual history were true, that the gay community has responded in some way to mitigate this now. However, one thing that will not help the process of minimising the suffering caused by HIV/AIDS and AIDS related illnesses is misinformation about the manners and mechanisms in which HIV is spread and the risk factors involved, so I can get very annoyed when in response to statements like:
To be honest, for 'men who have sex with men' it's more risky, that's just a fact unfortunately, not a matter of prejudice.
I see people write things like:
So that explains why the fastest growing HIV infection rates are amongst the straight community who are freely allowed to give blood?
or in response to :
Is it not more likely down to risk assessment than bigotry?
Statements like this:
No - the questionnaire doesn't address risk behaviours; have you had sex with a man since 197something? Banned - shagged a female whore without condom last night? No one asks ...
And slightly less annoying but quite interesting is:
It's a homophobic policy based on homophobic assumptions. Rigorous tests are carried out on donated blood. A ban when someone who's heterosexual could just as well be carrying the HIV virus reinforces prejudice.
I think we have a number of closely related questions here:
  1. Is Male/Male sex more likely to transmit the HIV virus? And as a consequence are men who have sex with men (commonly referred to as MSM) more likely to be carrying it?
  2. Is HIV incidence really rising faster among heterosexuals than among homosexual men in the UK? And if so what is the cause?
  3. Since it is all rigorously tested before use, why are we concerned about the potential for HIV to be present in the blood anyway?
  4. Is the lifetime ban on giving blood motivated by fact or simple homophobia?
Fortunately, one thing that didn't come up is the denial that HIV causes AIDS. No one reading this blog or who is a friend of any of my friends believes that particular regrettably oft-repeated piece of bullshit do they? No? Good; then we can proceed.

Q1. Is Male to Male sex more likely to transmit the HIV virus? And as a consequence, in the UK, are men who have sex with men (commonly referred to as MSM) more likely to be carrying it?

A1. Yes. Yes they are.

Oh you need more than that? OK.
The HIV virus is transmitted through bodily fluids. It cannot live for long outside the body, and therefore needs to get into the body either directly into the bloodstream through a wound or in an injection, or through the mucous membranes, which are delicate tissues found in the mouth, nose, eyes, ears, vagina, urethra and anus. Since I've not heard of a lot of nasal, aural or ocular sex, hetero or homo, I think we can safely forget about those, and concentrate on those in the more fun orifices. The primary difference we concerned with here is the difference between vaginal and anal intercourse; from International HIV/AIDS charity Avert's FAQ:
Unprotected anal intercourse does carry a higher risk than most other forms of sexual activity. The lining of the rectum has fewer cells than that of the vagina, and therefore can be damaged more easily, causing bleeding during intercourse. This can then be a route into the bloodstream for infected sexual fluids or blood. There is also a risk to the insertive partner during anal intercourse, though this is lower than the risk to the receptive partner.

Check out these stats from Avert. Let's focus on the Pie Chart at the top for now.
This chart shows the transmission method for all diagnosed cases of HIV in the UK up to 2010. It shows that for all sexually-transmitted cases of HIV, it's around about half-and-half homo/hetero, with a slight bias toward the straight. Superficially, this might be unexpected if, as most of us have, you've been exposed to information that suggests that HIV is more prevalent among homosexuals. However we need to think a bit harder. These figures are absolute numbers, and are therefore not proportional to the to the numbers of people that fall into those groups. Estimates of the percentage of people who are homosexual vary from about 3-10% of the population. For the sake of argument, we'll use the 10% figure.
In 2010 the total population of the UK would have been around 52,000,000, about 50/50 male/female.
If around 10% of the male population are homosexual that gives around 2.6M  homosexual males vs 23.4M hetero males, vs. 23.4M hetero females. We shall ignore lesbians, as transmission between this group is so low as to not feature in the statistics in any significant way. Now we need the absolute figures for HIV infections, which we can again get from the Avert statistics. Sex between men: 48,748; Sex between men and women: 50,184.

48,748 ÷ 2,600,000 ≈ 0.019 ≈ 2% of homosexual men infected with HIV.
50,184 ÷ 46,800,000 ≈ 0.001 ≈ 0.1% of heterosexual men and women infected with HIV.

making it twenty times more likely that a randomly selected gay man will be HIV infected than a randomly selected straight person of either gender. As it turns out, infection rates are higher among straight women than they are among straight men, so if we were to exclude women and compare gay men with straight men, this ratio would be even higher. Also, if we take a figure from the lower end of the spectrum of estimates of the proportion of gay to straight, such as 5%, this figure goes up to nearer forty times more likely even without splitting the genders.

So, in case we didn't already know this, we've learned two things. Anal sex is more likely to transmit the HIV virus than vaginal sex, and if a donor (or sexual partner) we choose is a (randomly selected) man who has previously had MSM sex, he is at least a factor of 20 (and probably much greater) more likely to be carrying the HIV virus than a man who hasn't.

One common response to bare assertions of the fact that anal sex among homosexuals is more likely to transmit HIV is the petulant  "Well explain why HIV infection rates are increasing faster among heterosexuals then!" as seen above, which leads us nicely to the next question, where we shall see exactly why.

Q2. Is HIV incidence really rising faster among heterosexuals than, among homosexual men in the UK? And if so what is the cause?

Let's go back to the data from Avert, but a bit further down the page:

It is clear from this data, that since 1999, the infection rate has been higher, in real terms, among heterosexuals than among the MSM group. Of course this doesn't take into account the ratio of homo to heterosexual people in the population. Were we to perform similar maths (an exercise for the reader perhaps?) to that in question 1 above, we would find that, even in 2004 when the number of heterosexuals contracting HIV was around twice that of homosexuals, the rate of infection within the group is still much higher, as a percentage of the total group size, among the MSM group than among the heterosexual. Even so "where are all these new cases coming from?" is a very pertinent question, and luckily one which was answered by the Health Protection Agency in 2007. They identified that the vast majority of these new infections in heterosexuals were acquired in sub-Saharan Africa, mostly by those emigrating from Africa, and mostly by women. While the reverse is true for the MSM group where most infections were acquired in the UK. So the short answer to "Why are heterosexuals getting infected with HIV at higher rates than homosexuals then?" is a) there are more of them, and b) they are catching it in Africa. And remember this is diagnosis rates, so such a sharp increase may be due to an increase in testing among heterosexuals, either in addition to or instead of any real increase in infection rates.

Another thing to notice is that since 2004 there's been a marked decline in hetero infection rates, this may be down to a number of factors (change in sexual practices due to increased awareness, less immigration from sub-Saharan Africa, passing the peak of cases revealed by increased testing, etc.) and while rates appear to have recently started declining slightly among the homosexual group, if current trends continue, hetero infection rates will be lower than MSM rates again in a few years.

Q3. Since it is all rigorously tested before use, why are we concerned about the potential for HIV to be present in the blood anyway?

Due to its small size, it is difficult to test for the presence of the HIV virus directly, so the most common form of HIV test, the ELISA antibody test, like the majority of HIV tests, does not directly check for the presence of the HIV Virus, but for the antibodies the immune system produces in an attempt to fight the infection. The problem here is that these antibodies are not normally detectable for 6-12 weeks after infection, and sometimes up to 6 months. So there is a "Window period" during which a person infected with HIV will pass the test with flying colours. There are other tests that can be performed, but these are either more complicated, and hence more expensive, to perform or they more often give false positives.

Short answer: Yeah it's tested, but the tests aren't 100% effective, it's safer to remove the risk earlier.

Q4. Is the lifetime ban on giving blood motivated by fact or simple homophobia?

One thing to notice about the questionnaire given to those who would give blood is that the words "gay" or "homosexual" never appear anywhere. In the interests of plain language they don't use "MSM" either. What it does say is "Are you a man who has ever had oral or anal sex with a man, with or without a condom?" This is a bare statement of a behaviour that indicates a risk. It is not a judgement on a person's sexuality or lifestyle. Of course you may interpret this as being a politically correct, coded statement, when what they really want to say is "URGH keep that fucking gay blood away from me!" if you wish to indulge a persecution complex, but that is clearly not its intent if you think a little more rationally. There is a follow-up question for women: "In the last 12 months have you had sex with a man who has ever had oral or anal sex with another man, with or without a condom?". So apparently the advisory committee responsible for these decision is so homophobic it won't even allow women who have slept with a bisexual guy to give blood!
There are several other criteria for who can give blood, despite what anyone may say. Our original poster for example was labouring under the misconception that it is fine for a straight man to have sex with a prostitute and give blood the next day. This is quite clearly not the case. You may not give blood if you have, in the last 12 months, had sex with anyone who has ever accepted money or drugs for sex. Of course this may not be clear if you were looking for the word "whore" in there somewhere ;) The questionnaire also forbids you from giving blood if: you have ever been a prostitute (even once) or have recently had sex with someone who has ever been a prostitute; you have ever been an intravenous drug-user or have recently had sex with someone who has; have had sex in an area where AIDS is common, or have had sex with someone else who has; have ever had hepatitis B or C or had sex with someone who has; recently had a tattoo, piercing or acupuncture; if you have visited somewhere where malaria is common or think you might be getting a cold. These are all, like the ban on MSM giving blood, because they indicate a high risk of the blood being contaminated with HIV or other blood-borne diseases; not out of prejudice against any of those groups, but because the risk factor of the blood being taken infecting the recipient is simply too high.

So the last question that I think remains unanswered is why, if it's only up to 6 months that the tests are ineffective, is the is the restriction on MSM blood permanent? Rather than just 6 months or one year like the limit after having had sex with someone who's had sex with someone from Africa? According to HIV/Sexual-health charity the Terence Higgins Trust, the most recent review decided that:
for example allowing MSM to donate if they haven’t had sex in the past year, this would still lead to the vast majority of gay men  being excluded from giving blood. The last review of the policy found that the risk to  the blood supply would rise by 60% if men were allowed to self assess based on these criteria. For this reason it was decided that a blanket ban was safer.

Another interesting note about the above graphs, is that infection of IV Drug users is tiny in comparison to those infected via sexual contact. So why are these people excluded from giving blood? Quite simply it's because a greater proportion of those who take drugs intravenously are infected and therefore, for the same reason the MSM group is excluded, they are excluded too. It simply isn't worth the risk; it's not prejudice, but like much in medical risk-assessments, it's a numbers game. HIV/AIDS, and some other infections such hepatitis B and C, are problems that disproportionately affect those who have anal sex, and homosexual men are having most of the anal sex, and homosexual men are disproportionately likely to be carrying the HIV virus. This is not bigotry; it is fact.

Of course anyone who wishes to deny services to gays based on these facts is bigoted arsehole, as is anyone who wishes deny services to someone who is HIV positive, beyond reasonable safety precautions,  regardless of their sexual orientation. And anyone who blames homosexuals for the spread of HIV, or tries to claim that AIDS is some kind of divine retribution for sin can just fuck off and die. But we mustn't allow the fear of being labelled as prejudiced to influence matters of public health, and so we exclude those in high-risk groups from giving blood regardless of whether any of those groups are persecuted minorities who are often the victims of bigotry or not. 

It turns out that earlier this year, the NHS revised their rules to a more sensible 12 month ban after MSM sex, bringing it in line with the currently available science, but keeping an all important period in which contracted diseases may not be detectable. Of course this probably won't mean that many more gay men can give blood, unless they've remained celibate for 12 months.

Further reading:

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