Ethnicity and infection: avoiding spurious associations

I’ve been meaning to blog on this editorial about ethnicity as a risk factor (or not!) for infection by Prof Leibovici in Clinical Microbiology and Infection for a while. The basic story is that “ethnicity” often falls out as associated with infection-related variables (e.g. colonisation or infection with resistant bacteria), but the editorial poses an important question: it is actually ethnicity, or something co-correlated with ethnicity (e.g. socio-economic status) that is the causal risk factor?

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ESBL likes Crowded House!

Just in case you aren’t yet sick of 1980s pop culture references on this blog, here’s another: ESBL likes Crowded House! Our study of more than 4000 admissions to a London hospital group found that 9% of patients carried an ESBL, and living in an area where overcrowded housing was common was an ESBL risk factor.

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Who’s looking for CPE in English hospitals?

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.

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CPE: a good reason to avoid surgery in Spain!

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…

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How to predict ESBL bloodstream infection?

Each day we prescribe antibiotics without knowing the specific cause of infection, yet. Some patients will have an infection caused by an ESBL-producing bug, and they would benefit from immediate treatment with a carbapenem or addition of an aminoglycoside. At the same time we don’t want to misuse carbapenems or hurt kidneys. Wouldn’t it be great if we could accurately predict who would need a carbapenem? Now you can. Continue reading

“Can I swab your rectum please?” ‘Pre-analytical’ factors skew prevalence studies

The analytical lab methods that we use to grow antibiotic-resistant bacteria make a big difference in terms of recovery. However, ‘pre-analytical’ factors are just as important in determining the sensitivity of prevalence studies. We are used to the idea of studies to work out the most sensitive anatomical site to sample for detecting colonisation with antibiotic-resistant bacteria. However, there are other ‘pre-analytical’ factors that may skew the findings of prevalence studies. A study from my old research group at KCL highlights how staff and patient choices, behaviours, and demographics can be pre-analytical factors that could skew prevalence studies.

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Chased by an antibiotic-induced C difficile-shaped shadow

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A fascinating new JAMA Internal Medicine study suggests that being admitted to a room when the prior occupant had taken antibiotics increases the risk of the subsequent occupant of the same room developing C. difficile infection (CDI). Quite a few convincing epi studies have showed that admission to a room when the prior occupant was known to have a number of key pathogens (including C. difficile) increased the chance of acquisition for the subsequent occupant. But this study extends the ‘prior room occupancy’ concept into a new dimension!

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