How much S. aureus is hospital acquired? Mk II

I posted a blog a couple of years ago (was it really that long!) on a fascinating study suggesting that only 1/5 of S. aureus in hospital patients is hospital-acquired. My key conclusion from that study was that the number of potential sources for S. aureus that the team investigated was inadequate to draw any firm conclusions (they didn’t include staff, surfaces, or visitors). I concluded that ‘the next frontier of transmission mapping must be a more comprehensive evaluation of other potential sources…’. The authors must have been reading, because this study from the same group was published recently in Lancet ID, which is a more comprehensive evaluation of other potential sources.

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Mycobacterium chimaera and heater-cooler units: a briefing

This post provides a briefing on the current status of the Mycobacterium chimaera issue related to heater-cooler units (HCUs) used in cardiothoracic surgery. You can download some accompanying slides here. Also, I found this recent ICHE review on the subject very helpful to bring me up to speed.

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The carbapenemase is out there

truth

A PNAS paper on the genomic diversity of carbapenemase producing bacteria in the US reports strong evidence of carbapenamase (an enzyme produced by bacteria that breaks down carabapenem antibiotics) activity but no sign of a carbapenemase gene. This provides a timely reminder that we are only really scratching the surface in our understanding of carbapenemases and how they work.

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The English C. difficile miracle: is it all about fluoroquinolones?

A new Lancet ID study suggests that restriction of fluoroquinolone usage has been the main driver of the national reduction in C. difficile infection in England. This paper is challenging in terms of some of the accepted approaches to controlling the transmission of C. difficile: if it’s all about reducing fluoroquinolones (and antimicrobials in general) and nothing to do with these measures, then why invest so much time and energy in isolation of symptomatic cases, cleaning and disinfection etc?

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Time to go shopping for a UVC system?

It is great to see the long-awaited ‘Benefits of Terminal Room Disinfection’ (BETR-D) randomised controlled trial of a UVC automated room decon (ARD) system published, in the Lancet, no less! This study firms up the importance of environmental contamination in transmission, and demonstrates additional benefit of UVC over and above enhanced conventional methods for VRE, maybe for MRSA, but not for C. difficile.

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The end of antibiotics

antibiogram-mueller-hinton

A case of pan-drug resistant NDM-producing K. pneumoniae CPE that resulted in a fatal infection in a US woman has prompted a lot of coverage and discussion on both sides of the Atlantic. Although this report is concerning, not least because the patient succumbed to the infection, this is hardly a new scenario. There are parts of the world where pan-drug resistant CPE are commonplace and have been for years (for example parts of India, the likely country of origin of the organism in this case). Before getting to the case report in detail, let’s take a moment to review this case series from India, published in 2014. 13 patients with pan-drug resistant Gram-negative bacteria (7 of whom were infected with K. pneumoniae, 4 of these 7 died) were reported in a specialist cancer treatment centre over 18 months over 2012/13. This evidence, from half a decade ago, shows that pan-drug resistant CPE is by no means a new phenomenon! Continue reading

The silent Mycobacterium chimaera epidemic

hcu

There has been much discussion about the risk of Mycobacterium chimaera infections associated with contaminated heater-cooler units (HCUs) used in cardiothoracic surgery. A study published recently in CID explores the risk in the UK, and provides further evidence to link these tricky-to-treat infections to contaminated HCUs.

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