Wednesday, May 29, 2013

Screening inpatients for MRSA—case closed.

It isn't often that you see a headline like this in the medical world.  But such are the conclusions reached by Michael B. Edmond, M.D., M.P.H., and Richard P. Wenzel, an editorial in the New England Journal of Medicine.  The editorial commented on the results of an extensive study by Susan S. Huang et al published by NEJM, entitled, "Targeted versus Universal Decolonization to Prevent ICU Infection."

This is a big deal. For a number of years, people have been arguing over the issue of whether screening patients for methicillin-resistant Staphylococcus aureus, or MRSA, with subsequent isolation, would be better than a generalized (non-pathogen specific) infection control approach.  As explained by Edmond and Wenzel, that study concluded:

Active detection and isolation without decolonization was not effective in reducing rates of MRSA-positive clinical cultures, MRSA bloodstream infections, or bloodstream infections from any pathogen. In contrast, targeted and universal decolonization resulted in significant reductions in MRSA-positive clinical cultures and bloodstream infections from any pathogen but not MRSA bloodstream infections; however, the effect of universal decolonization was greater than the effect of targeted decolonization.

The study design was as follows:

We conducted a pragmatic, cluster-randomized trial. Hospitals were randomly assigned to one of three strategies, with all adult ICUs in a given hospital assigned to the same strategy. Group 1 implemented MRSA screening and isolation; group 2, targeted decolonization (i.e., screening, isolation, and decolonization of MRSA carriers); and group 3, universal decolonization (i.e., no screening, and decolonization of all patients). Proportional-hazards models were used to assess differences in infection reductions across the study groups, with clustering according to hospital.

The results:

Universal decolonization resulted in a significantly greater reduction in the rate of all bloodstream infections than either targeted decolonization or screening and isolation.

(Note: Universal decolonization was accomplished with intranasal mupirocin for 5 days and chlorhexidine bathing for the entire ICU stay.) 

The editorial concludes (with my emphasis):

The implications of this study are highly important. The lack of effectiveness of active detection and isolation should prompt hospitals to discontinue the practice for control of endemic MRSA. A benefit will be a reduced proportion of patients requiring contact precautions, which is a patient-unfriendly practice that interferes with care. In addition, the folly of pursuing legislative mandates when evidence is lacking has been shown, and laws mandating MRSA screening should be repealed.

Lastly, this study has implications beyond MRSA. New resistance mechanisms continue to emerge in nosocomial pathogens. The recent dissemination of carbapenem-resistant Enterobacteriaceae has stimulated calls to implement active detection and isolation for these organisms. We hope that the results of this study will redirect that discussion and reinforce the utility of horizontal interventions to control not only the pathogens of today but those of tomorrow as well.


Diana Lenore Miller said...

From Facebook:

In California we are mandated to screen all patients for MRSA if they meet certain criteria. The hospital I work for stopped isolating MRSA positive patients and went to a decolonization approach in 2011. It did reduce the nosocomial infection rates. maybe this study will help change practice if it is disseminated widely.

@Bob_Wachter said...

From Twitter:

Imprtnt @NEJM study on #MRSA prventn discus'd by @Paulflevy Key point: folly of politicos legislting medical practice

@HaleyDoc said...

From Twitter:

‏@Paulflevy Gotta love it when dogma meets evidence- Screening inpatients for MRSA—case closed.

Nancy Thomas said...

Will a $40 per patient "solution" meet with widespread acceptance -

Anonymous said...

Universal Decolonization with Mupirocin: is this a good way of stimulating emergence of mupirocin resistant MRSA ?. Is it a closed case from this perspective ?