[Outbreak of multi-resistant Escherichia coli on a surgical ward: course, measures and consequences for future admissions of contaminated patients]

Abstract

In the period July-September 2003, a multi-resistant Escherichia coli strain caused an outbreak on a surgical ward in the Deventer Hospital, the Netherlands. This strain produced a beta-lactamase with an extended spectrum, making it resistant to third generation cephalosporins. Furthermore, the strain was resistant to trimethoprim-sulphamethoxazole (co-trimoxazole), gentamicin and quinolones, so that only treatment with carbapenems was possible. 8 patients were colonised. Genotyping of the strains by means of amplified fragment length polymorphism indicated the spread of a single strain. A multidisciplinary crisis team coordinated the infection control measures and the communication to involved persons and the press. Control measures consisted of contact isolation of colonised patients and extra attention to hand hygiene. After this proved to be ineffective, all patients on the ward were screened and the ward was closed for several days. The outbreak was stopped by strict cohorting ofthe colonised patients. There were no indications for transmission of resistance genes by plasmids. Several months later, on visiting the outpatient clinic, 3 other patients appeared to have been colonised by the epidemic E. coli strain during their admission. They had not been screened because they had already been discharged when all patients on the ward were screened for colonisation. In a follow-up study 9 months after the outbreak, 3 of the 6 investigated patients, who had in the meantime returned home, were still found to be colonised. Such patients constitute a risk for the re-introduction of multi-resistant bacteria into the hospital and should be preventively screened and isolated on admission.