I was recently browsing through the HCAI mandatory reporting data in England (as you do) and noticed that the increasing trend in E. coli BSIs and MSSA BSIs seems to be following a similar trajectory. Could the drivers of these two distinctly different organisms be similar?

The figure below shows the number of C. difficile infections, E. coli BSIs, MRSA BSIs, and MSSA BSIs reported in England via the mandatory reporting HCAI scheme.

Figure: Findings of the HCAI mandatory reporting scheme in England.

Some observations:

• It looks like MSSA BSI and coli BSI are rising at a very similar rate, in the backdrop of dramatic falls and then a plateau in C. difficile infection and MRSA BSI.
• There’s evidence of seasonality in coli BSI, but not in MSSA BSI.
• PHE don’t report on ‘Trust-attributed’ (i.e. post-48 hour) or ‘non-Trust-attributed’ for MSSA BSI and coli BSI in the publically available raw data (although they do in the annual epi summary, here – as you can see, both Trust and non-Trust attributed cases are rising).
• Could a common link driving both MSSA BSIs and coli BSIs be a reduction in antibiotic prescribing in the community (see ESPAUR report)? You’d like to think that the majority of reduced antibiotic use is inappropriately prescribed in the first place, but this will not always be the case.
• Or could this be changes in the population demographics (e.g. aging population), and more invasive procedures?

I would be interested to hear your views on why MSSA BSI and E. coli BSI seem to be rising, and whether there could be common drivers (that we can address).