Andrew Stimpson, 25, said yesterday that he was willing to do all he could to help to tackle the condition, after it emerged that his body had apparently rid itself of the human immunodeficiency virus.

Mr Stimpson, a Scot living in London, was found to be HIV-positive in August 2002, but 14 months later a blood test suggested that he no longer carried the virus. A further three tests confirmed the finding.

Doctors believe that this first confirmed case of “spontaneous clearance” of HIV could offer important insights into the behaviour of the virus, and possible means of defeating it.

To date there has been anecdotal evidence of such a clearance of HIV — in a handful of cases in sub-Saharan Africa — while two patients in the 1980s appeared to shake off the virus. However, in those instances it was impossible to prove that the positive and negative blood tests came from the same person.

Mr Stimpson, who was seen at the Chelsea and Westminster Healthcare NHS Trust, in London, has agreed to undergo further tests with doctors to identify exactly what has happened. According to Mr Stimpson, he suffered depression after the initial diagnosis but otherwise he was well and took no medication apart from dietary supplements.

A spokeswoman for the Chelsea and Westminster trust confirmed yesterday that Mr Stimpson had an HIV-positive diagnosis, followed by a negative test, but she stopped short of saying that he was cured.

She insisted that there was no chance a mistake had crept into the testing system. “Those tests are both accurate, the positive and a negative; they are correct,” the spokeswoman said, adding that doctors had asked Mr Stimpson to undergo further clinical investigation to find an explanation.

Mr Stimpson, who is originally from Largs, Ayrshire, tried to sue the trust after being told of his negative status, believing the initial diagnosis to have been wrong.

However, an investigation by the NHS Litigation Authority concluded that the trust’s Victoria Clinic for Sexual Health had no case to answer because both tests had been correctly conducted.

In a letter to Mr Stimpson, the authority said that the “fact you have recovered from a positive antibody result to a negative result is exceptional and medically remarkable”.

Mr Stimpson told two Sunday newspapers that he felt special and blessed to have escaped a condition that he had thought was a death sentence.

“It was so shocking, because you just never expect that,” he told the News of the World. “There are 34.9 million people with HIV around the globe and I’m just one person who managed to control it, to survive it, to get rid of it from my body.

“That is unbelievable. I think I am the luckiest person alive.”

Clinicians and other sexual health specialists said yesterday that Mr Stimpson’s decision to undergo further tests could reveal more about the workings of the disease.

Patrick Dixon, of the international Aids group Acet, said that if the unidentified mechanism that had combated the virus could be replicated, then it could offer a new approach to beating the disease.

Deborah Jack, the chief executive of the National Aids Trust, added a note of caution for other HIV sufferers, saying that it was impossible to draw any wider conclusions before further tests were conducted.

“The virus is extremely complex and there are many unknowns about how it operates and how people’s bodies react to it,” she said. “If this case were able to shed further light, it could be extremely valuable for research into treatments or a cure.”

HOW KILLER VIRUS TOOK HOLD

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