ICU-Onset Clostridium difficile infection in a university hospital in China: a prospective cohort study.

Xiaohui Wang,Zhiyong Zong,Lin Cai,Rujia Yu,Wenzhi Huang,Andrew Mcdowell

doi:10.1371/journal.pone.0111735

Xiaohui Wang, Zhiyong Zong + Show 4 more

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https://doi.org/10.1371/journal.pone.0111735

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Abstract

A prospective study was conducted to investigate the incidence, clinical profiles and outcome of ICU-onset CDI in a 50-bed medical ICU at a university hospital in China. Stools were collected from patients who developed ICU-onset diarrhea and was screened for tcdA (toxin A gene) and tcdB (toxin B gene) by PCR. CDI cases were compared with the ICU-onset non-CDI diarrhea cases for demographics, comorbidities, potential risk factors, major laboratory findings and outcomes. Stool samples from CDI cases were subjected to C. difficile culture and C. difficile isolates were screened for tcdA, tcdB and the binary toxin genes (cdtA and cdtB) using multiplex PCR. Strain typing of toxigenic C. difficile isolates was performed using multilocus sequence typing. There were 1,277 patients in the ICU during the study period and 124 (9.7%) developed ICU-onset diarrhea, of which 31 patients had CDI. The incidence of ICU-onset CDI was 25.2 cases per 10,000 ICU days. ICU-onset CDI cases had similar features with ICU-onset non-CDI diarrhea cases including the use of proton pump inhibitors and antibacterial agents. The crude mortality rate of ICU-onset CDI was 22.6%, but the attributable mortality rate of ICU-onset CDI was only 3.2% here. Toxigenic C. difficile isolates were recovered from 28 out of the 31 patients with CDI. cdtA and cdtB were found in two strains. Seventeen STs including 11 new STs were identified. All of the 11 new STs were single-locus variants of known STs and the 17 STs identified here could be clustered into 3 clades. The incidence of ICU-onset CDI here is similar to those in Europe and North America, suggesting that CDI is likely to be a common problem in China. Toxigenic C. difficile here belonged to a variety of STs, which may represent a significant clonal expansion rather than the true clonal diversity.

Highlights

Clostridium difficile, a Gram-positive spore-forming anaerobic bacterium, is the leading cause of nosocomial diarrhea in industrialized countries [1,2]
There were 1,277 patients in the intensive care units (ICU) and 124 (9.7%) developed ICU-onset diarrhea, of which 24 had a stool sample that tested positive for tcdA and tcdB (A+B+) and 7 had a sample positive for tcdB only (A-B+)
The incidence of ICU-onset C. difficile infection (CDI) was 25.2 cases per 10,000 ICU days, which is close to the 32 cases per 10,000 ICU days found in a medical ICU in the USA [10]

Summary

Introduction

Clostridium difficile, a Gram-positive spore-forming anaerobic bacterium, is the leading cause of nosocomial diarrhea in industrialized countries [1,2]. CDI has been well recognized in Europe and North America [1,4], little is known about the prevalence of CDI and the clonal relatedness of C. difficile isolates in China [5]. This may be due to the lack of awareness and the absence of laboratory capacity to detect this nosocomial pathogen in most hospitals in China. ICU patients may have a poor outcome when they developed CDI as they usually had comorbidities [6]. Studies on the incidence and outcome of CDI cases in ICU are scarce [6]. Available studies are typically retrospective and might underestimate the incidence

Material and Methods

Findings

Results, Discussion, and Conclusions