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Tuesday, June 18, 2013

Universal decolonization for the win against MRSA

MRSA (methicillin-resistant Staphylococcus aureus) is a huge problem in hospitals. That’s because once the usually benign bacteria establish an infection, they are nearly impossible to kill. They are resistant to almost all modern antibiotics. Ordinarily, our immune systems can handle the bugs (they aren’t more virulent than nonresistant Staph). Unfortunately, that isn’t always the case for hospital patients, who not only may be more immunologically vulnerable, but often offer easy access through open wounds or medical ports.

In an attempt to prevent MRSA from spreading in hospitals, health care workers have largely relied on two different methods. The first strategy was to screen specifically for MRSA, and then isolate and aggressively treat patients who test positive for the infection. The second is not to test for MRSA at all, but to follow universal decontamination procedures with every patient. 

In a large study published in the New England Journal of Medicine, these two techniques went head to head. Universal decolonization (removing all bacterial colonies) was the hand’s down winner, reducing all bloodstream infections, including those caused by MRSA, by 44%.

To achieve those results, patients had their nostrils swabbed twice a day with mupirocin antibiotic gel and were wiped down with chlorhexidine-impregnated antiseptic cloths. Hospital staff practiced standard contact precautions. 

One possible reason for the success of this method is the very fact that health care workers don’t have to wait for the results of tests before implementing treatment strategies. Everyone is wiped and swabbed, and as a result, the infection rate plummets.

I should point out that the doctors aren’t (yet) advocating that every person who enters a hospital submit to a full body strip and wipe down. All the procedures were done only on patients admitted to their hospital's intensive care units. I wouldn’t be totally shocked if that were to change, though.

More on this from Maryn McKenna at Wired Science.

Image: 2005 scanning electron micrograph (SEM) depicted numerous clumps of methicillin-resistant Staphylococcus aureus bacteria, commonly referred to by the acronym, MRSA; Magnified 9560x.

Huang, S., Septimus, E., Kleinman, K., Moody, J., Hickok, J., Avery, T., Lankiewicz, J., Gombosev, A., Terpstra, L., Hartford, F., Hayden, M., Jernigan, J., Weinstein, R., Fraser, V., Haffenreffer, K., Cui, E., Kaganov, R., Lolans, K., Perlin, J., & Platt, R. (2013). Targeted versus Universal Decolonization to Prevent ICU Infection New England Journal of Medicine DOI: 10.1056/NEJMoa1207290.