A strain of HIV that is resistant to two types of treatment has been discovered in America.

Four men in Washington state were diagnosed with strains of highly-resistant HIV (HR HIV) between 2005 and 2006.

Researchers now say that these strains are very similar, indicating that the four men may have had sex or shared injection equipment with common partners.

Of the 16 HR HIV cases diagnosed by Seattle King -County Public Health Department, the recent four cases found have proved resistant to more anti-HIVdrugs than the other 12.

This means that once the four men contract AIDS, treatment for them will be extremely limited.

Dr. Peter Shalit, director of HIV/AIDS research at Swedish Medical Centre and member of gay rights group GLAAD, claims that the new strain may also be able to spread more quickly and easily that previous types of HR HIV.

As it is unusual for four men with no know connection to each other to have the same strain of the virus, the Public Health Department fears that the new form of HIV may still be spreading quickly through the community.

The only other multi-drug resistant strain of the virus known to health authorities was a single case in New York in 2005.

Lisa Power, Head of Policy at Terrence Higgins Trust said, “Multi-drug-resistant HIV is the result of treatment, which fails, either because the drug is not strong enough, or because it is not taken at the right time. Multi-drug-resistant strains of HIV can be passed on.”

Bob Wood, HIV/AIDS programme director for the Seattle King -County Public Health Department, says “This is mostly about behaviour. Men who have sex with men need to know that drug-resistant strains can and are being transmitted and may be much less treatable,” sccording to the Seattle Post Intelligencer.

All four men have had multiple male sexual partners and have used methamphetamine, known as crystal meth.

Wood, a gay HIV+ man, claims that unsafe sex has recently increased within the local gay community, particularly amongst drug users.