As December rolls around, it's time to get out the red ribbons. Not just for Christmas but to remind ourselves, on World Aids Day, that more than 33 million people are infected with an entirely preventable virus. That's supposed to be good news: UNAids (the UN's HIV/Aids programme) has cut its estimates from 39.5 million last year. The bad news is that in many parts of the world we are still doing all the wrong things.
In India, a massive survey that tested nearly 100,000 people for HIV has found that men are far more likely to be infected than women, calling into question the "women bear the brunt" refrain that is part of World Aids Day. In truth, in countries where 90% of the world's population live, HIV is a man's virus. Men spread HIV to one another as well as to women. Except in rare cases, women get infected only by men.
HIV spreads most easily when drug injectors share needles and syringes, and most drug injectors are men. The virus spreads easily through anal sex, and again, the majority of people who have anal sex are men. People who sell sex and buy it are also at high risk, and buyers (who are almost all men) outnumber sellers (mostly women) by a factor of 10. In all of Asia, Latin America, Europe, North Africa and the Middle East, most HIV-related risk comes from sexual relations.
That leaves sub-Saharan Africa, home to 68% of the world's HIV infections, and to 83% of the women who live with the virus. Six out of 10 Africans with HIV are women. But even in Africa, the easiest way to whittle away at the HIV problem is surely to work with men.
Last week, I went to a global meeting on Aids and gender in Nairobi. There was a lot of talk about women's vulnerability, about their inability to refuse sex or use condoms, about the need to empower women. The implication was that if women weren't so poor, if they were better educated, if they had better access to services, they would be able to put a stop to this epidemic. But that doesn't square with the facts. In 16 out of 17 African countries, HIV infection rates are highest among women in the richest households. In two-thirds of those countries, educated women are more likely to have HIV.
Don't get me wrong. I think education and earning opportunities for women and more equality within couples are wonderful goals in their own right. But with close to 7,000 new HIV infections every day, we can't wait for equality to prevent HIV. And we don't need to.
Take the oft-quoted success story of Thailand. Thailand started a campaign to increase condom use in commercial sex as far back as 1989. It focused on men. Mostly the men who owned brothels, threatening to shut them down if they didn't enforce condom use. Brothel owners put the screws on men who bought sex, and they put on condoms.
More condoms on men meant that fewer sex workers got infected, fewer clients got infected, and fewer of the women those men married got infected. Thailand estimates that this campaign prevented 5.3 million infections among men between 1990 and 2007. That in turn prevented 2 million infections among women.
Thailand succeeded because it started with the people who had most power - brothel owners. In almost all societies, men have more power than women. They can already refuse sex or use condoms. Obviously, many don't, especially in some African countries where over a quarter of adults are already infected.
The belief that newly empowered women would be more likely to refuse sex or use condoms than already empowered men rests on the questionable assumption that women care more about staying alive. Plenty of men do act to protect themselves: gay men in the west, men who buy sex in the east, men who inject drugs. Do we really believe that it is not possible to work effectively with African men to help them protect themselves and the women they have sex with? Or have we just become so wrapped up in women's empowerment that we have forgotten to work with men, who also have an interest in preventing HIV?
Elizabeth Pisani, an epidemiologist who has spent more than a decade working on HIV in developing countries.