Martin Wroe: Stopping Aids takes more than a scare campaign. It takes leadership

Complacent governments are still standing by as a global pandemic unfolds

The Rev Canon Gideon Byamugisha is a Ugandan priest, living with Aids, and making no secret of it. Twenty years to the day since the death of Terrence Higgins – one of the first people in the UK to die with Aids – the Anglican cleric was in Britain last week, campaigning for people to recognise the global pandemic that the disease now represents.

Two decades ago it was the religious community which condemned the disease as a judgement of God on gays. Today, if you still believe in a God like that, you'd have to think he was judging all of Africa too, and getting ready to scythe down China, and then maybe vent his wrath on India and Russia. You could probably argue he hasn't finished with western Europeans either.

But if the ignorance and fear that attended the emergence of Aids in the early 1980s have been tempered with the passing of time, it is complacency and ignorance that now combine to hasten its dispersal. If Aids is no longer the "gay plague", the world has yet to wake up to the fact that it is on course to become the most lethal disease in history. In the two decades since the human immunodeficiency virus was identified, more than 20 million people have died of Aids, and another 40 million been infected with HIV. And that is not the worst of it.

According to a UN report published on Friday, there will be 45 million new HIV infections within eight years and – unless billions of dollars more are invested in prevention – 68 million more deaths in 18 years. In Barcelona later today, former US President Bill Clinton, US Secretary of State Colin Powell, and former President of South Africa Nelson Mandela will hear specialists at a global Aids conference warn that the epidemic is only in an early phase. HIV prevalence is leaping higher than previously thought possible in the worst-affected countries, and it is rapidly spreading into new populations in Africa and Asia, the Caribbean and eastern Europe.

"It's frightening," says Peter Piot, executive director of UNAids. "It is by far the biggest epidemic that humanity has known in absolute terms." And yet despite the research, the terrifying statistics and the sombre political rhetoric, we continue to underestimate what is happening. Surveys from 60 countries suggest more than half of those aged 15 to 24 do not understand how HIV/Aids is transmitted. In countries most at risk, as few as a fifth of young people know how to protect themselves. Half of all new infections are in people aged 15 to 24. In western Europe, consoled by expensive if arduous treatments that allow people to return to work, to live long and have rewarding lives, we are slowly but surely forgetting the safe sex messages we once couldn't escape.

While some cling to old myths about transmission (toilet seats and kissing), our guard is lowered by believing new ones. A new ICM poll finds that a third of British 18- to 24-year-olds believe there is a cure. For some that will be a fatal misconception. If the "iceberg" campaigns of the 1980s still ring dimly in the memory of thirty- and fortysomethings, they carry no resonance for the young. Sexually transmitted diseases are on the rise – cases of gonorrhoea and syphilis are doubling – and exposure to any one such illness inevitably increases vulnerability to more serious ones such as HIV. But the message is no longer getting through. The latest National Survey of Sexual Attitudes and Lifestyles reports an increase in the numbers of sexual partners, a lower age at which people first have sexual intercourse, increasing levels of heterosexual anal sex and of payment for sex – which are all associated with HIV transmission. Of the estimated 33,500 UK citizens living with HIV, nearly 10,000 are undiagnosed. This is fatal ignorance.

And as complacency in the prosperous world increases susceptibility, most of us continue to have little inkling of the catastrophic consequences for millions of the poorest people. The agonisingly slow journey from poverty of many developing nations is juddering to a halt as teachers die, hospitals are stripped of staff, businesses close, relatives tend their sick and children are orphaned. Life expectancy in sub-Saharan Africa is 47 years – without Aids it would be 62 years.

Despite the surfeit of sobering information, political action bears no relation to political rhetoric. Last year, UN Secretary General Kofi Annan launched the $10bn (£6.5bn) Global Fund to reverse the spread of HIV/Aids by 2010. To date, it has a mere $427m in the coffers. Incredibly Bill Gates, with a commitment of $100m, has pledged nearly as much as the super-rich G8 economies of France and Germany, promising $130m each. History's richest country, the US, is offering a paltry $500m. And the longer Western countries bury their heads in the sand, the more dependent the poorest countries will become, and the more Aids appears a two-tier global disease.

In the West 25,000 died of Aids last year but half a million people with the virus received drug treatment. In the poorest countries, six million people need antiretroviral therapy – just 230,000 are receiving it. Aids killed 2.2 million people in Africa alone last year.

The eventual, reluctant decision of some pharmaceutical companies to reduce prices in developing countries is extending treatment – cheaper "off patent" drug copies will help more. But in places where people can't afford an aspirin, monthly antiretroviral therapies remain a dream for most. When the rock singer Bono recently travelled in Africa with US Treasury Secretary Paul O'Neill – a calculated bid to spotlight the crisis of Aids to a navel-gazing US public – he met a young man in Soweto, fit and healthy, thanks to a Médecins-sans-Frontières programme of antiretrovirals.

Jonah's wife had died of Aids leaving him with two children, but his new partner was also HIV positive – and not part of the programme. Jonah had a dilemma, explained Bono. "He said he could share his drugs with her and they would both die slowly. Or he could give his drugs to her knowing that his children would lose their other parent to Aids. Or, he said, 'I can keep the drugs and lose the woman I love.' That's a decision that no civilised world should ask Jonah to make."

But while Africa is perforated with agonising cameos like this, conversely it also offers some of the best signs of hope. In Uganda, for example, the candid leadership of people such as Gideon Byamugisha and a government committed to investing in sex education have delivered an impressive reduction in prevalence rates. Overriding cultural and religious inhibitions, sex education has leapt up the list of social priorities and better-educated young people have modified behaviour. In 1989, some 85 per cent of young men said they had started having sex by the age of 18, while in 1995 it had fallen to just over 50 per cent. In the same period, the rates of adult women who had ever used a condom rose from 6 per cent to 39 per cent. Infection rates dropped from 8 per cent in 1999 to 5 per cent in 2001. Zambia is on course to become the second African country to reverse the spread of the disease, while a similarly vigorous programme of promoting safer sex in Senegal has kept HIV levels low. China, by contrast, is still in denial, which explains why HIV infections rose by 67 per cent in the first six months of last year, with 850,000 people living with the disease.

If the UK does not face anything like this kind of crisis, it is clear that until the Government makes sexual health a higher priority in modern schools, ignorance will persist and rates of transmission continue to rise. While the world continues to wait for a vaccine, which even optimists put 10 years away, decisive government can turn epidemics around – and prevent new ones emerging. Aids rides the back of poverty, injustice and ignorance. Improving aid and boosting trade for the poorest countries will enable them to fund better education and functioning health care systems. Western governments must urgently find the funds. It is not just morally right: it will be cheaper to pay now than later. Somewhere down the line a vaccine will be found, but the world cannot afford to wait.