A clear simple study has a stark headline: 16% of admissions to a Spanish surgical ICU carry CPE. This sort of carriage prevalence is at a ‘practice-affecting’ level: the empiric antibiotic choices may be altered and you begin to wonder what is left when the first signs of infection develop in almost 1 in every 5 patients…
The retrospective analysis of CPE carriage identified through a routine admission screening programme was performed on a surgical ICU in a 1300 bed hospital. 254 patients had a rectal screen collected over 2 years (2012-2013), and 41 (16.1%) carried CPE. A total of 46 individual CPE isolates were detected (5 patients carried multiple CPEs); K. pneumoniae (85%) and OXA-48 (76%) predominated. Risk factors associated with the carriage of CPE following multivariable analysis were: 3rd / 4th gen cephalosporins in the past 6 months (with a towering odds ratio of 28!); a beta-lactam or beta-lactamase inhibitor in the past 6 months, abdominal surgery in the past 12 months, and prior digestive / biliary endoscopy. 22 of the 41 patients developed an infection with the same CPE as detected on the rectal screen at the time of ICU admission; the study doesn’t report any outcomes from these studies, unfortunately.
A couple of points of particular concern:
- The increased risk associated with digestive / biliary endoscopy is a bit of a worry – and makes me wonder about exactly how they are decontaminating their endoscopes, following some high-profile endoscope-associated outbreaks. I was surprised that this hypothesis was not aired in the discussion.
- They used a pretty crude method to detect carbapenem-resistant bacteria: MacConkey agar plus cefotaxime. In our universal screening study in London, this method detected only 20% of CPE that were grown on chromogenic media. Could it be that the true prevalence of CPE on this unit was 5x higher?? (I certainly hope not, but it was almost certainly higher than detected using these methods.)
- This study was performed in 2012/2013 – now almost half a decade ago. I can only image that the prevalence of resistant bacteria have increased during this period, as they have in invasive pneumoniae infections reported to EARS-Net from Spain (see the Figure below). There has been a sharp increase in carbapenem-resistance in K. pneumoniae in the national invasive infection dataset reported to EARS-Net since 2012/13 (from 0.8% in 2012 to >2% in 2015)!
Figure: Trends in carbapenem resistance in invasive infections caused by K. pneumoniae in Spain
If you had a quick trip to Spain over Easter, perhaps a rectal swab is in order…