Staph infection not only seems to be more widespread, but also is more resistant to treatment with antibiotics than in the past, according to the report in the October 17 issue of the Journal of the American Medical Association (JAMA).
"Infections with significant antimicrobial-resistant pathogens, the types formerly seen only in hospitals, now have onset in the community. Old diseases have learned new tricks," the report read.
The study also found that infections from methicillin-resistant Staphylococcus aureus (MRSA) appear to affect certain people more often than others.
MRSA has become the most frequent cause of skin and soft tissue infections among patients in hospital emergency rooms across the United States, and can also cause severe, sometimes fatal invasive disease, according to the JAMA article.
The research, carried out by scientists at the Centers for Disease Control and Prevention, studied subjects in nine separate localities between July 2004 through December 2005.
They identified 8,987 cases of invasive staph infection, most of which were "health care-associated." Of those, 5,250 cases (58.4 percent) were "community-onset infections," while 2,389 (26.6 percent) were "hospital-onset infections."
But 1,234 cases (13.7 percent) were deemed "community-associated" illnesses, while another 114 (1.3 percent) could not be classified.
Overall, the JAMA study found, the incidence rate of invasive MRSA for 2005 was 31.8 per 100,000 persons. Most at risk were people older than 65 (127.7 per 100,000), African-Americans (66.5 per 100,000), and males (37.5 per 100,000).
Rates were lowest among children between the ages of five and 17 (1.4 per 100,000).
Of 8,987 observed cases of MRSA, 1,598 resulted in hospital deaths, the researchers said.
Extrapolating from that figure, they estimated that some 94,360 invasive MRSA infections occurred across the United States in 2005, of which some 18,650 were fatal.
The researchers called for new collaborations between the public health and medical communities to control antimicrobial resistance, and advocated "population surveillance ... by public health personnel working with hospitals and laboratories."
"Clinicians also should be encouraged to report to the health department any new trends in antibiotic resistance that they identify, the JAMA study read.