From 2005 to 2008, the rate of MRSA (methicillin-resistant Staphylococcus aureus) infections dropped by almost 28% among hospitalized patients and 17% among people who were not hospitalized but acquired the infection following medical procedures like dialysis.
The figures are based on an analysis of data from nine metropolitan areas across the U.S.
The CDC estimates that about 1.7 million health-care-related infections occur annually in the U.S., resulting in 99,000 deaths.
Multidrug-resistant MRSA infections have been among the most deadly, killing thousands of people each year.
The latest analysis is based on data obtained from the CDC's Emerging Infections Program/Active Bacterial Core surveillance system and represents the largest attempt to track infection rates across the country.
The research appears in the Aug. 11 issue of the Journal of the American Medical Association.
"This is really good news," CDC medical officer Alexander J. Kallen, MD, who led the study, tells WebMD. "It suggests interventions aimed at reducing infections in health care settings are having an impact. But much more needs to be done."
Health-care-related exposures were responsible for 82% of all MRSA infections identified in the analysis.
Overall, the nine surveillance sites reported 21,503 invasive cases of MRSA from 2005 through 2009, with just over 17,500 classified as health care-related.
The biggest declines during the period were seen in the most deadly MRSA infections -- those that invaded the bloodstream. Bloodstream infections dropped by about 34% among hospitalized patients and 20% among other health care-related exposures during the four-year study period.