EPIDEMIOLOGY OF AN OUTBREAK DUE TO GLYCOPEPTIDE-RESISTANT ENTEROCOCCUS-FAECIUM ON A LEUKEMIA UNIT

The clinical and molecular epidemiology of two clusters of colonizatio n and infection of patients by glycopeptide-resistant enterococci (GRE ) on a leukaemia and bone marrow transplantation unit was studied over a two-and-a half-year period. Thirty-five patients became colonized, of whom six developed clinical infections. Of the 53 isolates of GRE, 49 were Enterococcus faecium, multiply-resistant to vancomycin and amp icillin. DNA fingerprinting of 48 E. faecium isolates by pulsed-field gel electrophoresis identified six DNA types. One strain of VanB pheno type E. faecium predominated during the initial outbreak, and an unrel ated strain of the VanA phenotype was present in a second cluster. Env ironmental and patient isolates of E. faecium were indistinguishable b y DNA typing. The VanA phenotype enterococci probably arose by transfe r from the renal ward at a nearby hospital, and a patient with persist ent diarrhoea may have contributed to contamination and cross-infectio n. GRE may cause significant infections in immunocompromised patients, and are readily transmitted between them. GRE were controlled, but no t eradicated on the unit; infection control measures included improved environmental cleaning and modification of antibiotic use. In order t o control GRE, it is necessary to educate healthcare workers and imple ment the traditional, effective values of good personal hygiene and en vironmental cleanliness.