New research from the U.S. has found that a potentially deadly bacteria, a type of drug-resistant staph infection, is being transferred between gay men by way of sexual activity.
The researchers say sexually active gay men are spreading a form of Methicillin-resistant Staphylococcus aureus (MRSA) in the San Francisco area where they are 13 times more likely to be infected with the bacteria than men who are not gay.
At one time MRSA was confined to hospitals, nursing homes and other types of long term care facilities, but in recent times it has been appearing in public locations such as schools.
The researchers say staph infections that do not respond to antibiotics are very serious, and are becoming a problem in the U.S. and once such infections reach the general population, they can become "unstoppable".
Lead researcher Binh Diep, from the University of California, San Francisco says they believe the infection is spread through sexual activity and must be prevented.
In 2005, it was estimated that the 'superbug' killed about 19,000 Americans, more than were killed by HIV; the bacteria commonly cause boils and other skin and soft-tissue infections, but can also cause life-threatening and disfiguring deep-tissue infections and often has to be treated with expensive, intravenous antibiotics.
As many as 30 percent of people carry ordinary staph bacteria mostly in their noses, which can be passed by touching other people or by depositing the bacteria on surfaces or objects.
But community-based MRSA can live in and around the anus and is passed between sexual partners.
Diep says as with syphilis, rectal gonorrhea, and new HIV infections a person's likelihood of contracting MRSA increases with the number of sexual partners that they have.
Experts say the best way to avoid infection is by washing the hands or genitals with soap and water.
The study is published in the Annals of Internal Medicine.