Eight years ago when the Reverend Joe Humble, an Anglican clergyman, was told that he was HIV positive, his only wish was to 'crawl into the corner of a large London hospital and die'. A natural enough response for anyone, perhaps, yet in this case, his despair was compounded by the fact that he was 62 years old.

Aids is popularly believed to be a disease of the young, its cause rooted in youthful excess, and its particular tragedy the cutting short of young lives. Yet Mr Humble's situation is not unusual; 1,000 people over the age of 50 in the UK have been diagnosed HIV positive, and more than 700 have developed Aids - 11 per cent of the total number affected.

The real figure may be even higher. Tara Kaufmann, communications manager for Age Concern, and the author of A Crisis of Silence, a report on Aids, HIV and older people, believes that HIV is under-diagnosed and under-reported among the elderly. 'They're not going for testing, and they're not being tested when they get sick. If a 25-year-old man gets pneumonia, doctors will think it's suspicious, and they'll test for HIV. If he's 65, they won't'

Symptoms of HIV illness in older people may resemble other age-related illnesses; there is growing concern that dementia - often the first symptom of Aids in older people - is commonly mistaken for Alzheimer's disease. 'It's much more convenient if they've got Alzheimer's - much more respectable,' points out Joe Humble, acerbically.

The situation is aggravated by the fact that older people with HIV become ill and die much more quickly than younger people. In that respect at least, Joe Humble's experience is untypical. Nearly eight years after his diagnosis he has not experienced a single day of illness. 'I'm rather proud of the fact that I'm now in my 70th year. I'm a survivor, and I'm surviving this,' he says.

It has not been easy and the first year after his diagnosis was the worst of his life. Mr Humble had to complete six months of his contract as a chaplain to the Missions to Seamen in Buenos Aires. He did not tell anyone of his condition and was terrified of developing Aids and everyone finding out. 'I thought, they can't help at all, and they might even make things worse. I thought that this business of a trouble shared is a trouble halved is nonsense - it would just be a trouble doubled. It was very hard.'

According to Ms Kaufmann, this reaction is not uncommon. 'HIV is a terrible illness to suffer on your own, and older people are often very isolated - they're not mobile, they don't have large peer groups, and they cannot always tap into the existing networks of support.' Most of the HIV and Aids organisations target younger people, as the epidemic has hit the young the hardest. Yet Ms Kaufmann believes they are guilty of ignoring older people, though she concedes the prejudice can cut both ways. However willing Aids organisations are to open their doors to older people, many will refuse to use them.

The safer sex campaigns of the last decade have by-passed older people as well, for they are invariably pitched at a young audience. 'We've all been jumping up and down saying this is everyone's problem, but older people are a third of the adult population, and they've had no information targeted at them at all,' says Ms Kaufmann.

When Naomi Wayne, formerly chief executive of the Terrence Higgins Trust, became the director of Age Concern, Lewisham, she was shocked to discover that the available safer sex literature did not appeal to older men. 'We concentrated on the needs of younger men at the Trust, and it never crossed my mind that older gay men would not find what we produced attractive and interesting. But they don't - which means there is nothing available for them.'

The problem is complicated by the fact that older men who are having sex with other men are far less likely to have a 'gay identity' than the younger generation. They may not think of themselves as gay and many of them are married; they tend to regard Aids as someone else's problem. 'The ones I've met often dismiss it as something that young gay men get,' says Tara Kaufmann.

Older heterosexual men and women present a different challenge. 'If you've been married for 40 years, and you're having illicit sex on the side, you can't go home to your wife and suggest that you start practising safer sex,' Ms Kaufmann says. Nor is it realistic to suggest to a woman 'well past her menopause' that she should start using condoms. But clearly answers must be found. 'Unless we get some kind of peer education on safer sex, then we're going to put a lot of people at risk of HIV transmission,' she adds.

Yet the biggest group that has been overlooked are not people who are HIV positive themselves, or even at risk of transmission, but the parents, grandparents, partners and carers of those who are infected. Eva Hayman, a 66-year-old Catholic nun who runs the Terrence Higgins Trust Family Support Network, finds herself working more and more in what she calls 'a three- generational pattern', in which both parents and child are HIV positive, and the grandparents have become responsible for looking after them. The pressures are acute. 'It can be a devastating experience for someone in their sixties who is looking forward to retirement to find themselves as a full-time carer again. They may be wondering who will die first - my child? My grandchild? Or my son-in-law? And how will I cope with three funerals? Or will I die first - in which case who's going to look after the younger generation?'

But the picture is not entirely bleak. Eva Hayman is keen to stress that Aids can unite as well as divide a family. It may be that some grandparents will appreciate being back in a central role. Age may also prove to be a blessing for people who are diagnosed HIV positive. It certainly was for Mr Humble: 'I could retire without excuses at the age of 62, which I wouldn't have been able to do 20 years earlier,' he says. The fact that he was leaving Buenos Aires and returning to London - a break with past habits and old friends - gave him added impetus to make the changes that he felt were necessary. Freed from his heavy-drinking lifestyle, he resolved to do everything he could to look after his health.

'I decided that I wasn't going to give in, and let death overtake me. I said I'm going to live because that seems to me to be a godly thing to do.' He regularly attends a pastoral service for people with HIV and Aids, which includes a number of other older clients: 'I go there partly as a witness, to say, look - you don't have to die. It's an effort, and a continuing one, but keeping well is my hobby - I put a lot of time and trouble and money into it, and it pays off.'

'A Crisis of Silence: HIV, Aids and Older People' is available from Age Concern, 54 Knatchbull Road, London SE5 9QY (071- 737 3456) ( pounds 4 incl p&p).

(Photograph omitted)