Controversies in Hospital Infection Prevention: MRSA is a regional problem too.
Years ago, Belinda Ostrowsky, then at CDC, showed in the NEJM that VRE could be controlled through regional infection control efforts in the Siouxland region of Iowa, Nebraska, and South Dakota. David Smith, then at NIH, was motivated by this success to test whether this regional response was necessary for control of a generic hospital pathogen using mathematical models. (see his PNAS study). He found that regional coordination may be necessary. So what about MRSA? Hajo Grundmann and others in Europe have just published a very interesting paper in PLoS Medicine with an accompanying editorial by Frank Lowy. The authors collected MSSA and MRSA samples from 450 hospitals in 26 countries during 2006–2007 and completed spa typing on all of the isolates to determine genetic relatedness. They then geographically mapped the spa types. What they found was the unlike the widely distributed MSSA, dominant MRSA spa types formed distinctive geographical clusters within regions. Check out their interactive map (here). I think this shows that regional efforts will be required to control the spread of MRSA since it appears that it's mainly spread by patients who are re-admitted to different hospitals.
