@article {BrasgE632, author = {Ian Brasg and Marion Elligsen and Derek MacFadden and Nick Daneman}, title = {Predictive utility of swab screening for vancomycin-resistant Enterococcus in selection of empiric antibiotics for Enterococcus sterile-site infections: a retrospective cohort study}, volume = {5}, number = {3}, pages = {E632--E637}, year = {2017}, doi = {10.9778/cmajo.20170034}, publisher = {Canadian Medical Association Open Access Journal}, abstract = {Background: Swab screening for vancomycin-resistant Enterococcus (VRE) is used to identify VRE carriers and thus prevent transmission of this organism. We tested whether screening results could have unintended benefits in predicting the vancomycin susceptibility of subsequent Enterococcus infections experienced by these patients. Methods: We conducted a retrospective cohort study of all patients admitted to a large tertiary care hospital between 2010 and 2015 who underwent swab screening for VRE before experiencing an Enterococcus sterile-site infection. We derived test characteristics using the screening result as the test variable predicting the presence or absence of vancomycin resistance in the sterile-site Enterococcus species.Results: Culture results for sterile-site samples were positive for Enterococcus for 619 patients during the study period. Of these, 488 (79\%) had previously undergone VRE screening. A total of 19 (4\%) of the 488 screening results were positive for VRE, and 10 (2\%) of the sterile-site Enterococcus isolates were resistant to vancomycin. The overall specificity of VRE swabs was 97\% (95\% confidence interval [CI] 96\%-99\%), sensitivity was 70\% (95\% CI 35\%-93\%), the positive likelihood ratio was 28 (95\% CI 14-56), and the negative likelihood ratio was 0.31 (95\% CI 0.12-0.79). The post-test probability of vancomycin resistance in a sterile-site culture, given a positive result with VRE screening swab, was 37\% using study data and 83\% using published aggregate prevalence data for VRE in the United States. Interpretation: Prior VRE screening swab results represent a useful tool for predicting vancomycin resistance in sterile-site Enterococcus infections. Patients with a positive result for VRE screening swab and Enterococcus identified by culture of sterile-site samples should receive empiric treatment with linezolid or daptomycin until sensitivity results are available.}, URL = {https://www.cmajopen.ca/content/5/3/E632}, eprint = {https://www.cmajopen.ca/content/5/3/E632.full.pdf}, journal = {Canadian Medical Association Open Access Journal} }