The new Methicillin-Resistant Staphylococcus Aureus strain, named USA300, is particularly resistant to front line antibiotics. Often referred to in the media as the 'superbug', MRSA is generally transmitted from skin to skin contact and can also be spread by touching contaminated surfaces, but the germ appears to be transmitted most easily through intimate sexual contact.   

Dr. Binh Diep, PhD, a scientist at San Francisco General Hospital Medical Center and lead author of the report explained to the San Francisco Chronicle “his study found that up to 40 per cent of infections are occurring in the buttocks and genitalia, suggesting that the bug is spreading by sexual contact.”   

Although the Center for Disease Control has not labeled it as an STD, sexually active gay men have been reported to be 13 times more likely to acquire the disease than other parts of the general public.   

The USA300 strain was first discovered in 2001 and initially spread through injection drug users, prison inmates and the homeless, according to the San Francisco Chronicle. Today, the strain is being found among all types of population groups, including the gay community. Those with HIV seem particularly susceptible to MRSA infection.   

The germ typically causes boils and other skin and soft-tissue infections. Though Staph infections are treatable in many cases, MRSA can be serious enough to force amputation of infected limbs or lead to death. If MRSA infects the lungs, the infection can cause severe pneumonia that kills within hours, according to the Chronicle.   

The study reported in the Annals of Internal Medicine found the “highest concentrations of infection by the drug-resistant bug in and around San Francisco's Castro district and among patients who visit health clinics that treat HIV infections in gay men in San Francisco and Boston.”   

Dr. Chip Chambers, who co-authored the study, explained simple ways to avoid the spread of the staph infection. "Taking a shower after sexual contact may minimize contamination. Ordinary soap will do. It dilutes the concentration of bacteria. You don't need antibacterial soap."   

"Your likelihood of contracting each of these diseases increases with the number of sexual partners that you have," Diep explained to Reuters.   

Currently about one in 3,800 San Franciscans is carrying the disease according to research statistics.    

MRSA is responsible for the death of over 19,000 Americans in 2005, most of them in hospitals, according to a report published in October in the Journal of the American Medical Association.