Health officials in New York have discovered a man with a form of the virus that is resistant to three of the four drugs used to combat the disease.
Normally HIV can take up to 10 years before it develops into Aids, but the new strain damages the immune system at a far greater rate, so it becomes Aids within a couple of months.
US health officials are now frantically attempting to track down others who may have been infected by the man in New York. The man, who is in his mid-40s, is reported to have had multiple partners and also injected drugs.
Experts fear the new type of HIV could already be circulating in the population.
Virologists claim the strain could easily find its way across the Atlantic to Scotland if it cannot be contained.