I am the master of false assumptions…

When a hospital close by was affected by a VanB VRE outbreak, I suspected that my local hospital would be relatively immune, due to its smaller size, different patient cohort and relatively strict antimicrobial stewardship policies.

Of course, my assumptions were wrong! It didn’t take long for the VRE to gain a foothold locally as well. (I am simply carrying my poor form on from the COVID pandemic, where I also made several false assumptions…)

MDRO rates in NZ are relatively low compared to many parts of the world. Even though I work in a reasonably big laboratory covering a population of approximately 500,000, up until recently we could go a whole year between VRE isolates! It has therefore been a bit of a shock to see them appear on an almost daily basis over the past few months, fortunately all from rectal screening samples.

Enterococci are hardy bugs and survive well in the environment, necessitating meticulous cleaning with high-level disinfectant to minimise the risk of onward transmission. Despite our best efforts to date, we have struggled to get on top of the outbreak.

However, the news is not all gloomy. All our isolates so far have been from screening samples, and we have yet to see any clinical infections. Can you really call it an outbreak if you don’t have any clinical infections? Personally, I find it difficult to get excited about something like this unless the patients are clearly unwell.

The laboratory I work in serves secondary level care hospitals and we don’t have many of those highly immunocompromised patients with lots of lines in-situ who tend to run into problems with VRE. Our annual number of Enterococcus faecium bacteraemias is low and it may be that we will not end up with many VRE clinical infections even if it does become endemic.

VanB VREs are still amenable to several different treatment options such as linezolid, teicoplanin, daptomycin, etc. In terms of the MDRO spectrum, VanB VREs are on the milder end, at least on a population level. I would be a lot more worried about a CPE outbreak in the hospital.

It is also a good reminder to us that we cannot afford to relax in the field of antimicrobial stewardship. VREs are in particular selected out by the “3Cs”, namely (3rd generation) Cephalosporins, Ciprofloxacin and Carbapenems. We do well in controlling usage of the first two, maybe not so hot on the carbapenem front.

At the moment we are still trying to “stamp out” VRE from our local hospital. The financial cost and staff time involved in managing a VRE outbreak are not insignificant by any means. At some point, one needs to weigh up the cost-benefit analysis of an eradication approach…

Michael