Every so often a piece of research comes out that significantly affects our practice. It is refreshing to see that such research is still occasionally published, amidst the plethora of commerce sponsored papers that can be useful, but more often than not, are simply adverts.

Diverse Sources of C. difficile Infection Identified on Whole-Genome Sequencing. David W. Eyre et al.N Engl J Med 2013; 369:1195-1205.

This paper involves sequencing Clostridium difficile isolates from symptomatic patients over a 4 year period between 2007 and 2011 in Oxford Hospitals. 45% of the isolates were genetically distinct enough to suggest that their source was not from other patients symptomatic from Clostridium difficile infection.

The bottom line of this research is that it suggests that the epidemiology of Clostridium difficile is multi-factorial and that Infection Control measures will only go so far in controlling Clostridium difficile rates in hospitals. We also need to take such research into account when setting realistic targets for Infection Control teams to attain when addressing organisms such as Clostridium difficile.

These findings should not really surprise us that much… We know from previous carriage studies that approximately 10% of the population carry Clostridium difficile, so there are bound to be significant reservoirs in the hospital, peri-hospital and community settings. It may even be that some patients become infected with their own endemic Clostridium difficile strains, which are allowed to proliferate and produce significant amounts of toxin when the patient is challenged with broad spectrum antibiotics, thus creating an ecological niche for the Clostridium difficile bacteria. 

This study and another recent one on the laboratory diagnosis of Clostridium difficile have real implications from both a clinical and laboratory point of view on how we think about Clostridium difficile. As both these papers challenge established thought, they may not be readily accepted. From a lab point of view there may be a few grumbles because we may have to change and possibly increase our testing in light of these findings.

Both these papers need to be discussed in detail at departmental journal clubs, and not the interesting but highly isoteric environmental bacterium isolated on the blood culture bench for the first time in 10 years…

Michael