Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.

BACKGROUND: Changing clinical impact, as virulent clones replace less virulent ones, is a feature of many pathogenic bacterial species and can be difficult to detect. Consequently, innovative techniques monitoring infection severity are of potential clinical value. METHODS AND FINDINGS: We studied 5...

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Main Authors: Schlackow, I, Walker, A, Dingle, K, Griffiths, D, Oakley, S, Finney, J, Vaughan, A, Gill, M, Crook, D, Peto, T, Wyllie, D
Format: Journal article
Language:English
Published: Public Library of Science 2012
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author Schlackow, I
Walker, A
Dingle, K
Griffiths, D
Oakley, S
Finney, J
Vaughan, A
Gill, M
Crook, D
Peto, T
Wyllie, D
author_facet Schlackow, I
Walker, A
Dingle, K
Griffiths, D
Oakley, S
Finney, J
Vaughan, A
Gill, M
Crook, D
Peto, T
Wyllie, D
author_sort Schlackow, I
collection OXFORD
description BACKGROUND: Changing clinical impact, as virulent clones replace less virulent ones, is a feature of many pathogenic bacterial species and can be difficult to detect. Consequently, innovative techniques monitoring infection severity are of potential clinical value. METHODS AND FINDINGS: We studied 5,551 toxin-positive and 20,098 persistently toxin-negative patients tested for Clostridium difficile infection between February 1998 and July 2009 in a group of hospitals based in Oxford, UK, and investigated 28-day mortality and biomarkers of inflammation (blood neutrophil count, urea, and creatinine concentrations) collected at diagnosis using iterative sequential regression (ISR), a novel joinpoint-based regression technique suitable for serial monitoring of continuous or dichotomous outcomes. Among C. difficile toxin-positive patients in the Oxford hospitals, mean neutrophil counts on diagnosis increased from 2003, peaked in 2006-2007, and then declined; 28-day mortality increased from early 2006, peaked in late 2006-2007, and then declined. Molecular typing confirmed these changes were likely due to the ingress of the globally distributed severe C. difficile strain, ST1. We assessed the generalizability of ISR-based severity monitoring in three ways. First, we assessed and found strong (p<0.0001) associations between isolation of the ST1 severe strain and higher neutrophil counts at diagnosis in two unrelated large multi-centre studies, suggesting the technique described might be useful elsewhere. Second, we assessed and found similar trends in a second group of hospitals in Birmingham, UK, from which 5,399 cases were analysed. Third, we used simulation to assess the performance of this surveillance system given the ingress of future severe strains under a variety of assumptions. ISR-based severity monitoring allowed the detection of the severity change years earlier than mortality monitoring. CONCLUSIONS: Automated electronic systems providing early warning of the changing severity of infectious conditions can be established using routinely collected laboratory hospital data. In the settings studied here these systems have higher performance than those monitoring mortality, at least in C. difficile infection. Such systems could have wider applicability for monitoring infections presenting in hospital.
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spelling oxford-uuid:c761c44b-4632-4ba1-83df-4202b06345712022-03-27T06:44:43ZSurveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:c761c44b-4632-4ba1-83df-4202b0634571EnglishSymplectic Elements at OxfordPublic Library of Science2012Schlackow, IWalker, ADingle, KGriffiths, DOakley, SFinney, JVaughan, AGill, MCrook, DPeto, TWyllie, DBACKGROUND: Changing clinical impact, as virulent clones replace less virulent ones, is a feature of many pathogenic bacterial species and can be difficult to detect. Consequently, innovative techniques monitoring infection severity are of potential clinical value. METHODS AND FINDINGS: We studied 5,551 toxin-positive and 20,098 persistently toxin-negative patients tested for Clostridium difficile infection between February 1998 and July 2009 in a group of hospitals based in Oxford, UK, and investigated 28-day mortality and biomarkers of inflammation (blood neutrophil count, urea, and creatinine concentrations) collected at diagnosis using iterative sequential regression (ISR), a novel joinpoint-based regression technique suitable for serial monitoring of continuous or dichotomous outcomes. Among C. difficile toxin-positive patients in the Oxford hospitals, mean neutrophil counts on diagnosis increased from 2003, peaked in 2006-2007, and then declined; 28-day mortality increased from early 2006, peaked in late 2006-2007, and then declined. Molecular typing confirmed these changes were likely due to the ingress of the globally distributed severe C. difficile strain, ST1. We assessed the generalizability of ISR-based severity monitoring in three ways. First, we assessed and found strong (p<0.0001) associations between isolation of the ST1 severe strain and higher neutrophil counts at diagnosis in two unrelated large multi-centre studies, suggesting the technique described might be useful elsewhere. Second, we assessed and found similar trends in a second group of hospitals in Birmingham, UK, from which 5,399 cases were analysed. Third, we used simulation to assess the performance of this surveillance system given the ingress of future severe strains under a variety of assumptions. ISR-based severity monitoring allowed the detection of the severity change years earlier than mortality monitoring. CONCLUSIONS: Automated electronic systems providing early warning of the changing severity of infectious conditions can be established using routinely collected laboratory hospital data. In the settings studied here these systems have higher performance than those monitoring mortality, at least in C. difficile infection. Such systems could have wider applicability for monitoring infections presenting in hospital.
spellingShingle Schlackow, I
Walker, A
Dingle, K
Griffiths, D
Oakley, S
Finney, J
Vaughan, A
Gill, M
Crook, D
Peto, T
Wyllie, D
Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.
title Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.
title_full Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.
title_fullStr Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.
title_full_unstemmed Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.
title_short Surveillance of infection severity: a registry study of laboratory diagnosed Clostridium difficile.
title_sort surveillance of infection severity a registry study of laboratory diagnosed clostridium difficile
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