The number of severe infections by a "superbug," known as methicillin-resistant Staphylococcus aureus, is at least twice as high as researchers previously believed, and the bacterium now kills more Americans than AIDS, researchers reported today.
The antibiotic-resistant infections, commonly called MRSA, were once confined to a few hospitals, but a new study by the national Centers for Disease Control and Prevention found that in 2005 they made an estimated 94,000 Americans seriously ill and killed almost 19,000, compared with 17,000 who died of AIDS.
"Certainly, MRSA now has to be viewed as a very important target for prevention and control," said Dr. David A. Talan, an infectious diseases specialist at Olive View-UCLA Medical Center in Sylmar who was not involved in the study.
The infections have been a growing concern, particularly over the last decade, as they have spread outside hospitals, popping up in prisons, athletic fields and locker rooms.
The study reported that nearly 14% of new antibiotic-resistant staph infections are not linked to hospitals or other medical facilities, indicating that the disease has become ingrained in parts of the wider community.
The finding, reported in the Journal of the American Medical Assn., is the latest evidence of a widespread pattern of increasing drug resistance among a variety of infectious agents, including multi-drug resistant tuberculosis, antibiotic-resistant Clostridium difficile and other once-innocuous organisms.
Some hospitals, gyms and other public facilities have begun to implement more stringent infection controls to prevent the spread of the bacterium, such as more thorough scrubbing of equipment, using hotter water for laundry, banning towel sharing and increasing the use of disinfectants.
The bacterium also remains susceptible to some powerful and expensive antibiotics, such as vancomycin. But experts fear that the ability of the bacterium to mutate will outpace the ability of scientists to create new drugs.
The spread of resistant organisms is "astounding," Dr. Elizabeth A. Bancroft, an epidemiologist with the Los Angeles County Department of Public Health, wrote in an editorial accompanying the report.
Bancroft said the reported incidence of resistant staph infections is just "the tip of the iceberg" because the CDC researchers studied only blood-borne infections that find their way into internal organisms.
