According to the national Medical Research Council, the disease is the prime cause of death in the country and will kill between five and seven million people by 2010.

Most new HIV infections occur in 15 to 20-year-olds; more than half of children under 15 are expected eventually to die of Aids-related diseases. Kwa Shaka itself loses an average of five of its 1,200 students a year to Aids, and three teachers have died. One current teacher is known to be HIV-positive; others may be, but have not had the test.

A recent survey found that up to 20 per cent of teachers across KwaZulu-Natal are HIV-positive. 'Every Saturday,' says Kwa Shaka's principal, Themba Bhengu, 'I have to choose from a list of 10 funerals to go to. People are dying like flies.'

It might seem an unlikely place to find hope, but a pioneering programme at this school is turning even teenage gangsters into peer educators to combat the growing threat. They have a greater understanding of Aids and what it does to families than anyone their age should have.

Ayanda Kunene is an angelic-looking 18-year-old boy who tells his story in a low but unfaltering voice.

'My mother is HIV-positive, and since I've known about it I've regarded myself as an orphan. We had a bad relationship. I was rude and negative towards her and it would get worse when she'd say she wanted to commit suicide.'

He switched to Kwa Shaka six months ago because it was better academically than his former school. Soon after, he was invited to become a peer educator.

Ayanda joined Better Life Options, an HIV/Aids initiative that is run at his school and 40 others in four regions by the South African National Council of YMCAs, funded by Y Care International, the development agency of the YMCA movement. The programme has a daunting task in meeting the enormous information and life skills shortfall in a country ruled by a government that continues to deny its Aids pandemic. Nevertheless, more than 10,000 young people were involved last year.

'Since I joined, my relationship with my mother has changed and so has my whole attitude,' says Ayanda. 'I've been able to see my problem as a challenge. I realised it was up to me to change and that other people had bigger problems than me.'

Some of the peer educators have HIV themselves, others have close experience of it, still others become involved because they lack self-esteem or are engaged in activities such as gang membership, burglary, carjackings or prostitution.

The programme runs on the principle of all peer education work: if you put young people at risk in a position of responsibility, it raises their self-image and gives them a positive perspective on life and what they want to do.

In addition, the young educators are able to give information and discuss sensitive issues with other students more frankly than a teacher could.

In Better Life Options, the programme co-ordinator asks particular students from grades eight to 11 (aged 14 to 19) to become peer educators. Those who agree undergo a one-week training course, which includes an introspection exercise that encourages them to take stock of who they are, their behaviour and their aspirations.

They then take part in a range of activities that, in the words of Mpume Zama, programme co-ordinator for KwaZulu-Natal, 'equip them with the life skills they will need to cope with dangerous situations'.

'For instance, if they find themselves HIV-positive, we offer strategies for dealing with it,' says Mpume.

'We also give them information on HIV/Aids and sexual health generally as well as doing exercises that promote communication skills and strategies for resisting peer pressure. The focus is particularly on sexual relationships.' Once the training is complete, each educator is given a manual and meets with one class each week, with regular support and top-up training.

Sthembela Gumede, 18, is another whose work as a peer educator has made her aware of prejudice against people with Aids and how to combat it.

'I had a brother infected from 1997. He passed away three weeks ago. People believe they shouldn't be in contact with those who have Aids. News goes through the community that you're looking after someone with Aids and people are scared of you. Even my nephews wouldn't go near me or their uncle.

'I'm disturbed by young people believing the wrong things. It's our job to teach them.'

Children experience sex at an early age in the townships, sometimes when they are still in primary school. This is largely due to the general atmosphere of despair, a feeling there is nothing to lose, but also because of the material benefits of prostitution.

There are other reasons for the high incidence of infection among young girls. KwaZulu-Natal, which has the highest rate of HIV infection in the country, is also - not coincidentally - a stronghold of the myth that sex with a virgin is a cure for HIV: there are cases of infected fathers raping their two-year-old daughters in a desperate bid to save themselves.

Police estimate a rape is committed in South Africa every 80 seconds. According to a survey by Community Information, Empowerment and Transparency, an international non-government organisation, 27 per cent of girls don't consider it wrong to be forced into sex by somebody they know. Teachers raping girl students is commonplace. Thousands of girls are raped, assaulted and harassed at school each year but those responsible for the attacks are seldom punished, according to a report by the New York-based group Human Rights Watch, Scared at School: Sexual Violence Against Girls in South African Schools .

One in three women who said they had been raped cited their school teacher as the perpetrator.

Because school authorities are unable or unwilling to respond to complaints, girls often drop out of school to avoid facing the rapists. The report found teachers use their authority to sexually abuse girls, pressurising them to comply with promises of good marks, money or threats of beatings.

Girls are learning that sexual violence and abuse are an inescapable part of going to school, 'so they don't go', says Erika George, author of the report.

A 1998 survey in Johannesburg found that 20 per cent of young women had been sexually abused before they reached the age of 18; 68 per cent said the assaults had taken place in school or at work.

Despite the enormity of the problem, the South African education system has no personal, social and health education programme, sex education or any form of HIV/Aids information in the curriculum.

Nor are there counsellors to whom young people who have anxieties, who are HIV-positive or who have someone in their family who is ill, can turn.

It is no wonder schools are clamouring for outside help.

As Themba Bhengu puts it: 'It's a desperate situation. Our pupils feel despair. They say: 'We're all HIV-positive. The only difference is that some of us don't know for certain because we haven't had the test.'

'The result is that boys don't see the value of their own lives and some of our girls are encouraged by their mothers to go with older men so they can get money for groceries and school fees.

'Poverty kills the drive to learn because they think after passing their exams, 'What then? We're poor. There are no jobs and we're all going to die anyway'.'

But if someone like Joel Soni, 18, can have his ideas turned around, there is hope.

'I used to smoke a lot of dagga (cannabis) and come to school stoned and drunk. I'd leave early and go out stealing cars and stripping them down,' says Joel.

'Teachers encouraged me to join the YMCA programme, saying I could get useful skills. I said, 'What other skills do I need? I already know how to strip cars'.

'But the first session changed me. I was very moved when we did introspection exercises. I wanted to cry. I decided I wanted to be a role model for others, but that I couldn't affect others unless the change came from me first.'

'I think I have changed. I want to help others. Maybe I'll become a doctor.'