Doctors report that a new resistant type of staph bacteria appears to be spreading among gay men in major cities in the US, including San Francisco, Boston, New York and Los Angeles.
The difficult to treat bacterium, a variant of USA300 Methicillin-Resistant Staphylococcus aureus (MRSA), is resistant to drugs and has been found to be more common among gay men in these cities than among other populations.
The report is included in a study published in the journal Annals of Internal Medicine which says that the risk of gay men contracted the bug is 13 times higher than for other people.
The bacterium is thought to be most commonly transmitted by skin to skin contact during sexual activity. It causes boils and other skin infections, but can potentially be spread via the bloodstream to other areas of the body. Around 40% of the infections occur around the buttocks and the genitalia.
It only affects around 200 men a year in San Francisco, believed to be the epicentre of the infection, but doctors are concerned that it may spread further.
While the germ is resistant to six types of common antibiotics it can usually be treated through more aggressive means including surgical drainage.
Doctors recommend showering after sexual contact which may minimize contamination.