Invasive methicillin-resistant Staphylococcus aureus infections have declined in hemodialysis patients in the United States, according to researcher presented at ID Week 2012 in San Diego.

Researchers analyzed population-based data from nine U.S. metropolitan areas participating in Active Bacterial Core surveillance from 2005-2010. Through active laboratory-based case finding, the researchers identified 6,462 cases of MRSA. Cultures collected less than three days after admission was classified as inpatient and outpatient was all others.

Decrease in MRSA among dialysis patients
The incidence decreased from 6.5 to 4.4 per 100 dialysis patients; with an annual decreases of 6.5% for outpatient and 10.6% for inpatient.

Of 1,971 cases identified during 2009-2010, 92.7% were bloodstream infections; median age was 59 years,  54.0% were male, 57.4% were black, 97.4% underwent hemodialysis and 2.6% underwent peritoneal dialysis, and 70.8% were hospitalized in the year prior to the MRSA culture. Mortality within seven days of MRSA culture was 6.1%. Among hemodialysis cases, 60.9% were dialyzed through a CVC.

Incidence was calculated using dialysis population denominators from the U.S. Renal Data System. Annual changes in incidence over time were assessed using a generalized linear mixed model, controlled for age, gender and race.

"Because most cases had previous hospitalization, efforts to control MRSA transmission in hospitals might have contributed to the observed declines in both inpatient and outpatient cases," the authors wrote.

"Infection prevention measures should include fastidious vascular access care and efforts to decrease CVC use."

Researchers included: Duc Nguyen, MD, Fernanda Lessa, MD, Ruth Belflower, RN, MPH, Yi Mu, PhD, Matthew Wise, PhD, Joelle Nadle, MPH, Wendy Bamberg, MD, Susan Petit, MPH, Susan M. Ray, MD, Lee Harrison, MD, Ruth Lynfield, MD, Ghinwa Dumyati, MD, FSHEA, Jamie Thompson, MPH, William Schaffner, MD and Priti Patel, MD, MPH

The following schools and centers were involved in the research: Centers for Disease Control and Prevention, Division of Healthcare Quality Promotion, Atlanta; California Emerging Infections Program, Oakland; Colorado Department of Public Health and Environment, Denver; Connecticut Emerging Infections Program, New Haven; Atlanta Research and Education Foundation, Decatur; Emory University School of Medicine, Atlanta; Johns Hopkins Bloomberg School of Public Health, Pittsburgh; Minnesota Department of Health, St. Paul; Infectious Diseases, University of Rochester; Oregon Public Health Division, Portland; Vanderbilt University School of Medicine.