Asymptomatic Carriers of Toxigenic C. difficile in Long-Term Care Facilities: A Meta-Analysis of Prevalence and Risk Factors

作者：Ziakas Panayiotis D^*; Zacharioudakis Ioannis M; Zervou Fainareti N; Grigoras Christos; Pliakos Elina Eleftheria; Mylonakis Eleftherios

来源：PLos One, 2015, 10(2): e0117195.

DOI：10.1371/journal.pone.0117195

Background
The impact of Clostridium difficile colonization in C. difficile infection (CDI) is inadequately explored. As a result, asymptomatic carriage is not considered in the development of infection control policies and the burden of carrier state in long-term care facilities (LTCFs) is unknown.
Purpose
To explore the epidemiology of C. difficile colonization in LTCFs, identify predisposing factors and describe its impact on healthcare management.
Data Sources
PubMed, Embase and Web of Science (up to June 2014) without language restriction, complemented by reference lists of eligible studies.
Study Selection
All studies providing extractable data on the prevalence of toxigenic C. difficile colonization among asymptomatic residents in LTCFs.
Data Extraction
Two authors extracted data independently.
Statistical Methods
The pooled colonization estimates were calculated using the double arcsine methodology and reported along with their 95% random-effects confidence intervals (CIs), using DerSimonian-Laird weights. We assessed the impact of patient-level covariates on the risk of colonization and effects were reported as odds ratios (OR, 95% CI). We used the colonization estimates to simulate the effective reproduction number R through a Monte Carlo technique.
Results
Based on data from 9 eligible studies that met the specified criteria and included 1,371 subjects, we found that 14.8% (95% CI 7.6%-24.0%) of LTCF residents are asymptomatic carriers of toxigenic C. difficile. Colonization estimates were significantly higher in facilities with prior CDI outbreak (30.1% vs. 6.5%, p = 0.01). Patient history of CDI (OR 6.07; 95% CI 2.06-17.88; effect derived from 3 studies), prior hospitalization (OR 2.11; 95% CI 1.084.13; derived from 3 studies) and antimicrobial use within previous 3 months (OR 3.68; 95% CI 2.04-6.62; derived from 4 studies) were associated with colonization. The predicted colonization rate at admission was 8.9%.
Conclusion
Asymptomatic carriage of toxigenic C. difficile represents a significant burden in LTCFs and is associated with prior CDI outbreaks in the facility, a history of CDI, prior hospitalization and antimicrobial use. These findings can impact infection control measures at LTCFs.