Confronting CPE: the need for rapid diagnostics

Carbapenemase-producing Enterobacterales (CPE) infection rates in England have more than doubled since 2020 raising alarm but also requiring careful consideration.1 When examining these rates, there are important questions to ask: are we seeing more cases because healthcare providers are now paying closer attention and conducting more testing? Or does this reflect a genuine increase in CPE prevalence? The answer appears to be both. Enhanced surveillance and testing awareness represents progress, yet the underlying increase in CPE cases presents a significant challenge requiring strategic response.

CPE refers to a group of gram-negative bacteria that have developed resistance to carbapenems, a class of broad-spectrum antibiotics. Gram negative organisms, whether drug resistant or not, exist as part of normal flora and many are vital to us, contributing to the healthy functioning of our gut and other organ systems. The critical distinction lies in what occurs when individuals colonised with carbapenem resistant organisms become immunocompromised or face significant health challenges. In these circumstances, the probability of developing active CPE infection increases substantially.

Screening through rectal swabs identifies patients carrying these organisms before infection develops. Identifying these organisms enables implementation of appropriate infection control measures and informs treatment decisions should subsequent infection occur. In England, the "Big 5" carbapenemase families - KPC, OXA-48-like, NDM, VIM, and IMP - account for over 97% of CPE cases, with K. pneumoniae, E. coli, and Enterobacter species serving as the most common hosts.2 Understanding which carbapenemase is present directly impacts treatment decisions, as different resistance mechanisms respond differently to available therapies.