WASHINGTON — Drug-resistant staph bacteria picked up in ordinary community settings are increasingly acquiring “superbug” powers and causing far more serious illnesses than they have in the past, doctors reported Monday.
These widespread germs used to be easier to treat than the dangerous forms of staph found in hospitals and nursing homes.
“Until recently we rarely thought of it as a problem among healthy people in the community,” said Dr. Rachel Gorwitz of the federal Centers for Disease Control and Prevention.
Now, the germs causing outbreaks in schools, on sports teams and in other social situations, are posing a growing threat. A CDC study found that at least 10 percent of cases involving the most common community strain were able to evade the antibiotics typically used to treat them.
“They’re becoming more resistant and they’re coming into the hospitals,” where they swap gene components with other bacteria and grow even more dangerous, said Dr. Keith Klugman, an infectious disease expert at Emory University. “It’s really a major epidemic.”
The germ is methicillin-resistant Staphylococcus aureus, or MRSA. People can carry it on their skin or in their noses with no symptoms and still infect others — the reason many hospitals isolate and test new patients to see if they harbor the bug.
MRSA mostly causes skin infections.
But the germ can be life-threatening if it gets into the bloodstream, lungs or organs. Pneumonia, sinus infections and even “flesh-eating” wounds due to MRSA are on the rise, doctors reported Monday at an infectious diseases conference in Washington.
About 95,000 serious infections and 20,000 deaths due to drug-resistant staph bacteria occur in the United States each year.
To treat them, “we’ve had to dust off antibiotics so old that they’ve lost their patent,” said Dr. Robert Daum, a pediatrician at the University of Chicago.
The CDC used a network of hospitals in nine cities and states to test samples of the most common community MRSA strain, USA300, over the last few years.
MRSA usually is resistant only to penicillin-type drugs. But 10 percent of the 824 samples checked also could evade clindamycin, tetracycline, Bactrim or other antibiotics.