Pathogen-specific preventability?

As Mike pointed out yesterday, one of the interesting findings in the CDC CLABSI report is the difference in percent reduction by pathogen. The most dramatic reduction (73%) was found among Staphylococcus aureus, with more modest reductions among gram negative bacilli (37%), Enterococcus spp. (55%), and Candida (46%).

These findings, discussed in some detail in the MMWR report itself, are consistent with a point I made in a prior post on the preventability of CLABSIs. The CLABSI prevention bundle elements prevent infections due to organisms that gain access to the bloodstream from the catheter-skin interface. No amount of skin preparation, site care, sterile barriers and hand hygiene can prevent organisms from translocating across the gut wall of a seriously ill patient—and so far, no one has developed catheter material that can completely prevent such organisms from adhering once they do gain access to the bloodstream. Furthermore, many of the organisms that arise from gut or other peripheral sites will be misclassified as CLABSIs even if they never adhere to the catheter.

We should expect that interventions which focus on reducing bacterial burden at the catheter insertion site will have their greatest impact on skin bugs, and their least impact on common gut flora. As for getting to zero, it won’t happen until we have ways of addressing infection sources other than the catheter insertion site (and by “addressing”, I mean both improved prevention approaches and improved definitions).