Outbreak of vancomycin‐resistant Enterococcus faecium in a haematology unit: risk factor assessment and successful control of the epidemic

We describe an outbreak of vancomycin‐resistant Enterococcus faecium (VRE) on the haematology ward of a Dutch university hospital. After the occurrence of three consecutive cases of bacteraemia with VRE, strains were genotyped and found to be identical. During the next 4 months an intensive surveillance programme identified 21 additional patients to be colonized with VRE, while two more patients developed bacteraemia. A case–control study was carried out to identify risk factors for VRE acquisition. In comparison with VRE‐negative control patients (n=49), cases (n=24) had a longer stay on the ward during the year preceding the outbreak (25·8 versus 10·1 d, P=0·02), more cases with acute myeloid leukaemia [11 versus 4, odds ratio (OR) 9·5, 95% confidence interval (CI95) 2·4–32·2] and higher grades of mucositis (P=0·03). Logistic regression analysis identified antibiotic use within 1 month before admission (OR 13·0, CI95 2·1–80·5, P=0·006) and low albumin levels at baseline (OR 1·2, CI95 1·1–1·3, P=0·02) to be independent risk factors. Four patients with VRE‐bacteraemia were successfully treated with quinupristin/dalfopristin (Synercid®). Control of the outbreak was achieved by step‐wise implementation of intensive infection control measures, which included the cohorting of patients, allocation of nurses and reinforcement of hand hygiene.