An interesting modelling study has quantified the size of the CPE iceberg lurking under the water when CPE is only detected by clinical cultures and no active screening is done. And the CPE iceberg is larger than you may think!
A team of authors surveyed NHS acute hospitals in England to determine the approach to CPE detection, including laboratory methods. The findings provide an opportunity to compare the approach to CPE detection and prevalence nationally, identifying higher CPE prevalence in the North-West, North-East and the South-East (the region that includes London) of England. The findings also suggest that more screening for CPE would detect more carriers – and perhaps help to prevent a silent epidemic of CPE in some regions.
BMC Medicine has published some research from our group reporting the findings of a mathematical model comparing various approaches to screening for CPE carriage. The model compared how several operational metrics varied with different approaches to screening (‘slow and cheap’ laboratory culture vs. ‘fast and expensive’ PCR) and in various specialties with variable levels of compliance with CPE admission screening and at various levels of admission prevalence of CPE. The main conclusion was that culture proved to be the best approach in most scenarios, balancing risk and resource.
The current national guidelines for CPE in England recommend three serial admission screens each separated by 48 hours to confirm a negative carrier status combined with pre-emptive isolation. Even leaving aside the infeasibility of pre-emptive isolation, this approach introduces a host of operational challenges. In a study just published in JHI, we find report that serial admission screens do not improving the detection of CPE. However, there was a striking apparent increase in the rate of carriage of other resistant Gram-negative bacteria in the early days of hospital admission, suggesting either an unmasking of pre-existing carriage or acquisition of resistant Gram-negative gut flora.
I recently posted on the WHO CPE guidelines. A couple of people have alerted me to two other recently published guidelines, one from ECDC, and the other from Australian Commission on Safety and Quality in Healthcare. So, we now have a wealth of guidelines to prevent and control CPE. But how to they compare?
I heard an interesting talk by Dr Michael Miller last week on the ethics of screening for MDROs. Whilst we need to think carefully about the ethics of all medical procedures (great and small), I think the benefits to the individual and the population generally outweigh downsides for MDRO screening programmes.