A new strain of highly drug-resistant HIV that leads to the rapid onset of Aids has been detected in a New York man, it emerged today.

Health officials said they were not aware of a case like it, describing the strain as “difficult or impossible to treat”.

They warned it had the potential to lead to a serious public health problem.

The virus was found in a man in his mid-40s who had unprotected sex with other men, often while using crystal methamphetamine, an addictive stimulant, doctors said.

The city`s Department of Health and Mental Hygiene issued an alert to all hospitals and doctors to test every newly diagnosed HIV case for evidence of the rare strain while officials worked to track down the sexual partners of the victim.

The man`s HIV did not respond to three of four types of antiviral drugs most commonly prescribed.

Health Commissioner Dr Thomas Frieden said the onset of Aids appeared to have occurred within two or three months, and at most 20 months, after infection.

“We consider this a major potential problem,” he told the New York Times.

Dr Ron Valdiserri, deputy director of the Centre for Disease Control, said drug resistance was increasingly common among HIV-positive people, including some who had never been treated before, but not with such a fast progression to Aids.

He said that “double whammy” of resistance and rapid progression made the case alarming.

The man, who had not previously undergone antiviral drug treatment, was diagnosed with the virus in December.