The Wall Street Journal-20080115-Resistance of Superbug Grows- New MRSA Strain Hits Communities Of Gay Men Hardest
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Resistance of Superbug Grows; New MRSA Strain Hits Communities Of Gay Men Hardest
A highly drug-resistant superbug is gaining resistance to more drugs and burrowing deeply into the gay communities of San Francisco and Boston, researchers said.
Sexually active gay men are 13 times as likely to have this strain of the highly resistant bacterium, known as MRSA, or methicillin- resistant staphylococcus aureus.
More worrisome still, the new strain of MRSA called USA300 is growing resistant -- or unresponsive -- to three or even four classes of widely used antibiotics.
MRSA causes deep and stubborn skin infections and has been called the most common cause of skin infections treated in the nation's emergency rooms. It also more rarely can cause lethal invasive infections such as pneumonia or sepsis (blood poisoning).
Several drug classes that have lost their punch against the worsening strain include families that contain: penicillin, erythromycin, clindamycin, tetracycline and fluoroquinolone drugs such as Cipro, said Binh Diep, researcher at the University of California at San Francisco and first author of the study in the Annals of Internal Medicine.
The toughest strain also now is resistant to mupirocin, a topical antibiotic drug used to clear MRSA from the skin surface and nostrils where the bug is known to colonize even people without an infection.
The study emerged from a retrospective review of charts from 183 patients treated for MRSA at the San Francisco General Hospital's Positive Health Program, an outpatient clinic used by people with HIV, the virus that causes AIDS. An additional 130 patients were studied at Boston's Fenway Community Health clinic.
The review of charts found gay men age 18-35 to be hardest-hit. ZIP Codes around San Francisco's Castro District, a largely gay neighborhood, were heavily affected. Previously, MRSA infections have been documented in sports teams, prison populations, gym-goers and the community at large.
Skin-to-skin contact, including sexual relations, are believed to be major ways the bug spreads from person to person. But Henry "Chip" Chambers, chief of infectious diseases at SF General and a study co- author, said heavy antibiotic use is "the most important factor" that the superbug's toughest strain resides among gay men.
Unlike resistant infections of the past, which thrived mainly in hospitals, MRSA runs rampant through the community and can crop up in people with no recent antibiotic use.
"It's more virulent than standard staph," said Shelley Gordon, an infectious-disease specialist in private practice at California Pacific Medical Center. To avoid using the wrong drug and fueling even more resistance, she urged testing for drug resistance, adding, "doctors in emergency settings have to be hip to this and do cultures."
