There were an estimated 30,800 fewer invasive methicillin-resistant Staphylococcus aureus infections reported in the United States in 2011 compared with 2005, according to recent data published in JAMA Internal Medicine.
“This is encouraging news, as it suggests that organized efforts to reduce these infections are working,” Raymund Dantes, MD, MPH, who led the study while an epidemiologist at the CDC, told Infectious Disease News. “To continue bringing down the number of serious MRSA infections, we will need to learn more about how serious MRSA infections develop in the community.”
Dantes and colleagues estimated the incidence of invasive MRSA by using surveillance data from selected counties in nine states from 2005 to 2011. They also collected data on hospitalization and health care risk factors for the confirmed MRSA cases.
Infections were classified as health care–associated community-onset (HACO) if culture was obtained as an outpatient or on or before hospital day 3 among patients with documented health care risk factors. Hospital-onset infections were classified if culture was obtained after hospital day 3, and community-onset cases were classified if the culture was obtained in a patient without a health care risk factor as an outpatient or on or before hospital day 3.
The estimated national incidence of invasive MRSA is 80,461 in 2011: 48,353 were HACO, 14,156 were hospital-onset and 16,560 were community-onset. Compared with 2005, the estimated national rate decreased by 31.2% in all categories, with the highest decrease (54.2%) seen among hospital-onset infections. HACO infections decreased by 27.7% and community-onset infections decreased by 5%.
“I hope this study encourages health care professionals, including those who see patients and those who work on programs to prevent health care–associated infections, to continue their efforts to prevent MRSA infections,” said Dantes, who is now an assistant professor of medicine at Emory University. “It may also spur more research into understanding how to prevent serious MRSA infections in community settings.”
Dantes said more research is needed to understand community-associated infections because these numbers are relatively unchanged compared with health care–associated infections.
Raymund Dantes, MD, MPH, can be reached at Emory University Hospital, 1364 Clifton Road NE, Box M-7, Atlanta, GA 30322; email: firstname.lastname@example.org.
Disclosure: Dantes reports no relevant financial disclosures.