ABSTRACT
SUBJECT: The closed system PCR for the rapid detection of vanA and vanB genes (Xpert vanA/vanB Cepheid(®)) was evaluated in our laboratory, to improve the rapidity of the response and thus the management of patients and isolation measures during two GRE outbreaks. METHOD: From March to December2009, 565 samples were analysed by PCR associated to bacterial culture initially for all samples for 2months (n = 75), and thereafter for PCR-positive samples only. RESULTS: In this study, sensitivity and negative predictive values of the PCR were 100%. Specificity was evaluated in the presence and absence of outbreak: 69.3 and 76.8% respectively. The variability of false positive rates between units were lower in nonepidemic than during epidemic phase. The global false positive rate was 23.9%. CONCLUSION: This easy-to-use technology provides rapid results four samples are tested in 1h versus 72h for culture. Despite its reagent cost, it represents an important hospital diagnostic tool: improvement of the management of cohorting areas and patient transfer between units, adaptation of isolation measures and treatments. However, culture remains necessary to confirm any positive result obtained by PCR and for epidemiological surveillance.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Carbon-Oxygen Ligases/genetics , Computer Systems , Cross Infection/microbiology , Drug Resistance, Multiple, Bacterial , Enterococcus faecium/genetics , Glycopeptides/pharmacology , Gram-Positive Bacterial Infections/microbiology , Polymerase Chain Reaction/methods , Disease Outbreaks , Early Diagnosis , Enterococcus faecium/drug effects , Enterococcus faecium/isolation & purification , France/epidemiology , Gram-Positive Bacterial Infections/diagnosis , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/epidemiology , Humans , Laboratories, Hospital , Predictive Value of Tests , Sensitivity and SpecificityABSTRACT
OBJECTIVE: An outbreak of vancomycin-resistant Enterococcus faecium (E. faecium) occurred in the Bethune Hospital since March 2008 (two consecutive waves). To control this outbreak, two-point prevalence surveys were conducted in May 2008 and January 2009 in inpatients hospitalised more than 24 hours on previously non-affected wards. METHODS: In each ward, information was given to inpatients, administrative and medical data were collected, rectal swabs or stool samples were performed and cultured on chromogenic media. Data were anonymised, and Epidata software was used for the analysis. RESULTS: In May 2008, nine patients were found to be colonized with vancomycin-resistant E. faecium among the 239 patients evaluated (prevalence : 3.76%), and three new wards were affected: neurology ward, general surgical ward, and emergency department observation unit. In January 2009, only one patient, hospitalised in cardiac intensive care unit, was colonised among the 157 patients evaluated (prevalence 0.63%). CONCLUSIONS: These two-point prevalence surveys identified the reservoir of vancomycin-resistant E. faecium carriage, and were thus helpful to contain the two epidemic waves at the Bethune Hospital. A cohorting of the colonised inpatients was performed. Five secondary colonisation cases were detected among the 181 contact patients in May 2008, and no secondary case among 32 contact patients in January 2009.
