The number of people living with HIV in Oxfordshire has almost doubled in four years.

According to NHS managers, there were 364 known cases of the disease across the county last year, including nine patients under the age of 16 - a 96 per cent increase since 2002, when there were 186 sufferers.

But Oxfordshire Primary Care Trust has admitted it is unlikely that health workers will be able to reduce the number of newly diagnosed patients in line with targets set by the Government in 2002.

Five years ago, there were 70 new cases in 12 months, and the objective was to reduce the number by 25 per cent in five years.

But in 2006, 71 people were diagnosed, and managers believe the target of 53 for 2007 is doubtful.

The news coincides with World Aids Day today.

County public health director Dr Jonathan McWilliam said: "The target was set before improvements were made to services and we're in line with other areas. The world is now a global village and Oxfordshire is not immune to that. People come here who have illnesses. We welcome them and treat them.

"The increasing numbers of people living with the illness is also a tribute to the people who treat HIV. Drug therapy is improving considerably and more people are living longer as a result.

"One of the success stories is that 44 uninfected babies have been born to HIV mothers since 2004. This is due to the high quality care mothers receive during pregnancy and labour."

HIV is a virus which attacks the body's natural immune system, leaving sufferers vulnerable to the simplest of illnesses - even a cold can turn into serious pneumonia.

There is no cure, but drugs can improve a patient's life by helping to ward off the virus's effects.

In Oxfordshire, 67 per cent of sufferers contracted the illness through heterosexual sex, while 22 per cent are gay men who contracted it through sex. Children and injecting drug users are also among the infected.

The OPCT's sexual health and HIV strategy emphasised that better diagnosis was vital to prevent the virus spreading, and waiting times for an appointment at the genito-urinary clinic (GUM) had improved.

In 2005, only a third of patients received an appointment within 48 hours, but now 90 per cent are seen in two days.

Dr McWilliam said: "Around one third of people with HIV are still undiagnosed, so there's absolutely no room for complacency.

"The general advice is always use a condom and don't share needles if you are using drugs."

Jake North has lived with HIV for 12 years after a single night of unsafe sex.

As a result of his condition, he has lost friends, upset his family, started taking illegal drugs and suffered the stigma attached to HIV.

The 33-year-old said: "We need to increase the quality and frequency of sex and relationship education. That's very important. We also need to break down the stigma so people feel more comfortable talking about it.

"If you're sexually active, you need to be tested every six months. Although this advice is mainly for younger people with more partners, even monogamous people sometimes don't realise they've got the virus."

Mr North, 33, who lives in Oxford, is bisexual and although he was very promiscuous in his youth, he always practised safe sex.

He said: "I had a couple of friends who enjoyed the risk of unsafe sex, so I decided to try it. Once was enough to give me HIV.

"I didn't even know the guy's name, but he looked perfectly healthy and I didn't think he'd have the virus.

"Now I feel the responsibility is partly on me to stop it spreading. I want to scare other people into safe sex.

"Because of the improvements in treatment, there's a growing community of people living with HIV and that puts a huge strain on the NHS. It's also fair to say that the more people there are with HIV, the more chance of it spreading."