April 18, 2011 — Universal surveillance, contact precautions, hand hygiene, and institutional culture change are linked to reduced transmissions and infections of methicillin-resistant Staphylococcus aureus (MRSA) in a large Veterans Affairs (VA) healthcare system, according to the results of a study reported in the April 14 issue of The New England Journal of Medicine.

These results are similar to those found in a study, as previously reported by Medscape Medical News, that showed enhanced cleaning of intensive care units (ICUs) with disinfectant-saturated cloths, an educational campaign, and targeted feedback could decrease transmission of MRSA or vancomycin-resistant enterococci.

"MRSA Bundles" Effective

The current study indicates that "Health care–associated infections with ...MRSA have been an increasing concern in ...VA hospitals."

"A 'MRSA bundle' was implemented in 2007 in acute care VA hospitals nationwide in an effort to decrease health care–associated infections with MRSA," write Rajiv Jain, MD, from the Veterans Health Administration MRSA Program Office, Patient Care Services, VA Central Office, and the VA Pittsburgh Healthcare System in Pittsburgh, Pennsylvania.

"The bundle consisted of universal nasal surveillance for MRSA, contact precautions for patients colonized or infected with MRSA, hand hygiene, and a change in the institutional culture whereby infection control would become the responsibility of everyone who had contact with patients."

At each facility, staff entered aggregate data into a central database each month on adherence to surveillance practice, prevalence of MRSA colonization or infection, and healthcare-associated transmissions of and infections with MRSA. The investigators evaluated the effect of the MRSA bundle on healthcare-associated MRSA infections from October 2007, when the bundle was fully implemented, through June 2010.

During this period, there were 1,934,598 admissions to or transfers or discharges from ICUs (n = 365,139) and non-ICUs (n = 1,569,459) and 8,318,675 patient-days, including 1,312,840 ICU patient-days and 7,005,835 non-ICU patient-days. The percentage of patients who were screened at admission increased from 82% to 96%, and those screened at transfer or discharge increased from 72% to 93%. At the time of hospital admission, the mean prevalence of MRSA colonization or infection was 13.6 ± 3.7%.

Although rates of healthcare-associated MRSA infections in ICUs did not change in the 2 years preceding October 2007 (P = .50 for trend), there was a significant 62% decrease associated with implementation of the bundle, from 1.64 infections per 1000 patient-days in October 2007 to 0.62 per 1000 patient-days in June 2010 (P < .001 for trend). Rates of healthcare-associated MRSA infections in non-ICUs also decreased (by 45%) from 0.47 per 1000 patient-days to 0.26 per 1000 patient-days (P < .001 for trend).

"A program of universal surveillance, contact precautions, hand hygiene, and institutional culture change was associated with a decrease in health care–associated transmissions of and infections with MRSA in a large health care system," the study authors write.

Limitations of this study include lack of data to determine the extent to which each component of the bundle or concomitant infection–control initiatives may have contributed to the overall reduction in healthcare-associated infections.

"Although we did not make a formal cost–benefit assessment of the VA MRSA Prevention Initiative, others have reported that programs of active surveillance are cost-effective over a wide range of prevalence and transmission rates," the study authors conclude. "Expanding elements of the program to long-term and ambulatory care settings may be necessary to deal with reservoirs of MRSA throughout the health care system."

Opposing Study Findings

Another study, published in the same issue of The New England Journal of Medicine as the current study, reached nearly opposite conclusions. A 6-month intervention in 18 ICUs was ineffective in reducing the transmission of MRSA and vancomycin-resistant enterococci, but the use of barrier precautions by providers was less than what the intervention required.

In an accompanying editorial, Richard Platt, MD, from the Department of Population Medicine, Harvard Pilgrim Health Care Institute and Harvard Medical School in Boston, Massachusetts, suggests that the divergent results of the 2 current studies might be attributed to different study designs.

"It is also possible that the benefits Jain et al. observed were due to factors other than the MRSA bundle," Dr. Platt writes. "The VA system had introduced guidelines addressing ventilator-associated pneumonia and central-line–associated bloodstream infections in the previous year. It also issued a guidance document on decolonization of MRSA-colonized patients approximately 6 months after full implementation of the MRSA bundle, at about the time the dramatic drop in infections occurred. Interrupted time-series analyses incorporating the MRSA bundle and these other interventions might help elucidate the effect of the bundle."

Comments by Dr. John Jernigan, coauthor and the CDC's director of Healthcare-Associated Infection Prevention Research and Evaluation, are available as a CDC Expert Video Commentary on Medscape.

The study authors have disclosed no relevant financial relationships. Disclosure forms provided by Dr. Platt are available with the full text of this article at The New England Journal of Medicine Web site.

N Engl J Med. 2011;364:1419-1430, 1464-1465. Abstract Extract

Clinical Context

Clinical Implications

• An MRSA bundle intervention implemented at multiple acute care facilities increased MRSA screening at admission.
• The MRSA bundle is effective at reducing MRSA infection and healthcare-associated MRSA-infection.

CME Test