Johann Hari: People are dying because gay men can't give blood

When I was a student, I went along with a group of my friends to give blood, clutching my arm nervously. All summer, increasingly desperate adverts had been warning that NHS blood banks were on the brink of drying up, and I felt I had a debt to repay: a few months before, my grandmother had been hit by a car, and quarts of blood from anonymous donors saved her life.

The posters said: "Anyone with a heart can give blood." As we waited for the jab, we all filled in a questionnaire. My friends were led in one-by-one to donate – but I was taken aside and told: we don't want your blood. You're gay. The rules state: "You should never give blood if you are a man who has had sex with another man, even 'safe sex' using a condom."

If you have ever had gay sex, the NHS considers your blood contaminated for life. But a court case unfolding in Australia has exposed the bad science behind this ban – and shown that it endangers all of us, gay and straight.

The defenders of the ban have a superficially plausible case. All donated blood is obviously tested carefully – but it can take a few months for the HIV virus to show up. So if you only recently contracted HIV and you then give blood, you can unwittingly inject the virus into the blood bank. Gay men are seven times more likely to contract HIV than straight men. So it has been judged that the risk is simply too great.

They are right about one thing: safety is the first, second and third priority of blood donation. The whole point of giving blood is to save life, not endanger it. If gay donations really did endanger people, that would trump any commitment to anti-discrimination. Giving people Aids obviously would not be a price worth paying for equality.

But in reality, that dilemma doesn't occur. Earlier this year, a 21-year-old gay electronics technician called Michael Cain launched a court case against the Australian Red Cross after they refused to take his blood. He wants gay men who exclusively practice safe sex – like him – to be allowed to donate like everyone else. The scientists testifying at the trial included the doctor who first created the blood ban – who came to apologise. They explained that blood banks now have to choose between two competing risks. On one side is the high risk of people dying because they are given old, stale blood due to a lack of donors. On the other side is the infinitesimally small risk of people dying because they have been given blood by condom-wearing gay men.

The US epidemiologist and bio-ethicist Dr Scott Halpern crunched the figures for the court. Some 1 in 100 people who are infused with blood older than 14 days will die – and 13 per cent of infused blood offered by the Red Cross is older than that. This, he explained, poses a risk "thousands of times greater" than "the very worst predictions of HIV infection" if you let latex-loving gay men donate. Why? Because if the ban is lifted and gay men who practice safe sex are allowed to donate, a single HIV-positive blood donation will slip through clinical screening once every 5,769 years. That's one time between now and the year 7777 – or equivalent to it happening once since 3761 BC, when cities had not yet been invented.

So the facts are in: the ban kills far more people. Even Dr John Kaldor – the Red Cross's chief medical adviser – admitted the rules were "out of date." A country as institutionally and viciously homophobic as Russia has lifted the ban – yet in Britain it persists. In 2001, the head of our National Blood Authority, Mike Fogden, even dubbed gay men like me "evil" and said we are "prepared to put at risk the innocent life of an innocent patient (even a newborn child) to satisfy [our] own selfish prejudice."

But why? As Russell Hirst, a young gay British man, puts it: "I was very shocked that, when my sister got ill and needed a lot of blood, I wasn't allowed to donate it. I just want to be equal. Everybody should be judged on their personal activities. If a gay man says that he's had unprotected sex with a man, then he should not give blood for 18 months – but I don't see why it should be a lifetime ban." He's right. Our blood banks are running low, and we are locking three million donors out. Isn't it time to end this bloody homophobia – for all our sakes?

j.hari@independent.co.uk