I’m sure we’ve all been following the emerging story of the 2019-nCoV outbreak closely, with the third cases reported in the UK yesterday (pleased to see this is where you’d expect the UK to be based on Marc’s post earlier)! There’s been a small explosion of publications in the peer reviewed literature. I’ve chosen one slightly randomly to discuss today: a short modelling study providing some insight on the likely volume of unreported cases (very much the ice berg and not the tip!) and some sense of where this outbreak will end (it depends on how we respond, globally).
I posted at the beginning of last week about the emergence of the as-yet-formally-unnamed novel coronavirus that has emerged in China. At that stage, it could have been a parochial anomaly in the annals of ID history. What a difference a week makes! Now we are looking at a rapidly emerging international outbreak!
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.
The risk of interspecies transmission of carbapenemase genes is a real concern. We can barely get our heads around many different types of carbapenemase in a whole host of Gram-negative bacteria (compare the relative simplicity of methicillin resistance in S. aureus: a single gene, in a single species). Throw in interspecies horizontal transmission of carbapenemases and things get really tricky! Do we implement different control strategies to try to interrupt the transmission of carbapenemases (in contrast to the organisms themselves)? Could you have a multispecies outbreak of a carbapenemase on your hands and not even realise it?
A very enjoyable few days in Edinburgh this week for the Federation of Infection Societies / Healthcare Infections Society (FIS/HIS) meeting. Some reflections follow…
It’s the most Chunderful time of the year (or maybe not). The Norovirus ‘season’ will still be on us and a few points are well worth reflecting on. A recent systematic review of Norovirus risk in high and middle-income countries asserts that there may be as many as 12.5 million infections annually these countries alone, with possibly as many as 2.2 million outpatient visits related to the illness. Personally I have always liked having a bit of norovirus around. Keeps the staff on their toes and gives a good indicator of how IPC is really being performed rather than another set of 99% compliant hand hygiene audits.
Reported by Andreas Widmer in Basel and now published by Hugo Sax and colleagues (CID April 15th, 2015), the amazing story of open-cheat heart surgery, Mycobacterium chimaera infections (years after the operation!), and contaminated heater-coolers in your operating room.
While the Swiss were first, we know by now that this problem is unfortunately not limited to the Alp region, but furthermore present e.g. in the Netherlands. If your hospital has a program for open-chest heart surgery, now is the time to check your heater-coolers, to avoid further airborne transmission of M. chimaera from contaminated heater-cooler units.
The August edition of the Journal of Hosptial Infection Journal Roundup is now available, featuring:
- A whopping five-fold increase in the detection of CRE in 25 US community hospitals.
- MALDI-TOF as a new frontier for rapid detection of carbapenemase activity.
- More on fist bumping instead of hand shaking. (Would you like a fist bump greeting from your doctor? No thanks!)
- Triclosan-impregnated stitches would be cost-effective if they were only a little bit effective, but turns out they’re not effective at all.
- The new ‘crAssphage bacteriophage’, C. difficile biofilms, and increasing rates of antibiotic resistance – all in the human gut microbiome.
- Some hope for Ebola drug and vaccine targets.
- How to reduce the number of sickies that children take from school (through effective school-based immunization programmes).
- Thoughtful analysis on S. aureus outbreaks of old with lessons for now.
- Reviews of CRE mortality, global antibiotic use, microbial hitchhikers, overdiagnosis & overtreatment, useless reporting of science in the mainstream media, and whether biocide use drives biocide resistance.
I’ve written three editions of the Journal of Hosptial Infection Roundup now (June, July and August), so there’s a few examples to review. You can read about my methods for producing the Roundup in the blog accompanying the June edition. I thought that now would be a good time to get some feedback, specifically:
- Is the title right? A few people have expected it to be an overview of articles in the Journal of Hospital Infection only.
- Is the length about right? (Do you fall asleep reading it or find yourself begging for more?)
- Is the depth right? Or would you like to read more about less articles, or less about more articles?
Any feedback that you have would be most appreciated. Please either submit a comment below or email me.
Photo credit: ‘Fist bump’.
I recently came across a fascinating review article published in 1963 mainly about outbreaks of Salmonellosis during the 1950s. The review focuses on epidemics that were traced to contaminated surfaces, including ingested, contact and inhaled transmission routes. A number of interesting epidemics stand out:
- An outbreak linked to contaminated neonatal respirators.
- An outbreak linked to a contaminated chopping board (see Figure). In this outbreak, one of the investigators apparently contracted Salmonellosis after touching the chopping board during sampling and then having a cigarette before washing his hands.
- An outbreak (of microbial endotoxin syndrome) linked to a contaminated mouthpiece of SCUBA equipment. Here, the outbreak occurred in naval diving academy and the pattern of lessons and cases was so regular, that the epidemiologist could predict precisely when to visit to see the next case.
Figure: A chopping board at risk of persistent microbial contamination due to surface damage.
Although most outbreaks covered in the review relate to ancient catering-related outbreaks of Salmonella, there may be some useful learning for hospital epidemiology today, specifically CRE. It’s rare although not unheard of to find Salmonella carrying a carbapeneamase (i.e. Salmonella CRE). However, Salmonella is a member of the Enterobacteriaceae, so the involvement of contaminated surfaces during outbreaks of Salmonella suggests that contaminated surfaces may also be important during outbreaks of CRE.
It’s interesting that even back in the 1960s contaminated surfaces were recognized as potentially important in epidemics, whereas by the 1980s, the role of contaminated surfaces in endemic transmission was considered negligible. It’s difficult to know whether experts of the 1960s (perhaps there are some reading this?) would have considered contaminated surfaces important in both epidemic and endemic transmission? I suspect so, and we just lost sight of that in the 1980s and 90s.
Image: Ben Hosking.