National Glycopeptide-Resistant Enterococcal Bacteraemia Surveillance Working Group Report to the Department of Health - August 2004

1 From September 2003, acute National Health Service trusts in England have been required by the Department of Health to undertake mandatory surveillance of bacteraemias caused by glycopeptide-resistant enterococci (GRE). 2. In total, 4855 enterococcal bacteraemias (including 256 reports of 'Group D streptococci') were reported through the voluntary reporting system to the Communicable Disease Surveillance Centre (CDSC) in England and Wales in 2002, and 8.9% of the reports that contained information on vancomycin susceptibility indicated that the isolate was resistant to vancomycin. Most hospitals reported fewer than five GRE bacteraemias per year to the CDSC, with only 13 hospitals reporting more than five episodes per year, although there is undoubtedly an element of under-reporting. 3. This Working Group was established to review the methods used to identify and test the susceptibility of enterococci to glycopeptides, and to make recommendations on the reporting of GRE bacteraemias, as there were indications that current methods would not provide a suitable basis for this surveillance. 4. A review of methods was undertaken, including a national questionnaire on methods, approaches to testing and risk factors for GRE bacteraemia. This, together with data from routine laboratory reports and special surveys, revealed the following. - A significant proportion of enterococci are not identified to species level. - There are problems with identification of enterococci. Commercially available kits do not identify some enterococcal species reliably. - Not all laboratories test vancomycin susceptibility of enterococci from bacteraemia. This does not allow a robust assessment of GRE bacteraemia rates because the prevalence of glycopeptide resistance will be underestimated if laboratories test teicoplanin alone or no glycopeptides against enterococci. - There are technical difficulties in detecting non-VanA resistance in enterococci and this will also contribute to under-reporting of gtycopeptide resistance. 5. Clinically significant GRE infection is associated with a worse prognosis than infection with susceptible strains, but this factor has not been clearly separated from the possible influence of co-morbidities and antibiotic usage. 6. GRE bacteraemia occurs mainly on specialist units, particularly transplantation, renal, haematological malignancy and intensive care units. Hospitals with such units will inevitably have a higher risk of featuring prominently in surveillance studies. Hence, meaningful denominators for surveillance of GRE bacteraemia are required.