Researchers at the CCIDR, who are part of the CLAHRC South London infection team, have screened more than 4,000 patients in their first 72 hours of admission to Guy’s and St Thomas’ Hospitals to see if they are carrying a carbapenem resistant bug.
The researchers want to find out how many people admitted to hospital are carrying CRE, and whether those who are share any experiences (eg taking a course of antibiotics recently) to inform the development of a south London screening strategy.
Samples collected via rectal or perineal swabs have been tested using conventional microbiological culture techniques and a rapid test using PCR (polymerase chain reaction) methods to compare sensitivity and cost-effectiveness.
The analysis of samples taken from 816 patients who were screened over a four-week period show two per cent of patients were found to be CRE positive by PCR and 0.1 per cent by culture(4). ‘Although PCR is more expensive on a per test basis, it is considerably more sensitive than conventional culture for detecting CRE colonization at the time of hospital admission,’ says the research team(4).
Everyone who participated in the research was also asked to fill in a simple questionnaire at time of swab collection to help the team identify potential risk factors for carrying CRE.
Of the two per cent (14 people) who were carrying CRE, all were UK residents, most had either been abroad or hospitalized in the past year, or taken antibiotics in the past six months.
Most of the 14 would not have been screened by hospital staff who were following recommendations in the Public Health England toolkit. This suggests that ‘risk factors to trigger CRE screening require modification,’ says the research team(4).
‘If people are colonised or infected with CRE, they need to be identified and managed to stop the bacteria spreading to other patients,’ says Professor Mike Sharland who leads the CLAHRC South London infection research team. ‘Prompt identification of people who carry CRE is important to help prevent and control transmission in hospital.’
'The results of this study will help south London hospitals plan screening strategies and inform the choice of screening test.'
The team in the Centre for Clinical Infection and Diagnostics Research (CCIDR) is also working out how to investigate the behaviour and spread of antibiotic resistant GN bacteria outside of hospitals
This research is funded by Guy’s and St Thomas’ Charity with a small contribution from the CLAHRC South London.
(1) Acute trust toolkit for the early detection, management and control of carapenemase-producing Enterobacteriaceae, Public Health England, December 2013.
(2) Addressing the infection risk from carapenemase-producing Enterobacteriaceae and other carbapenem-resistant organisms – letter to acute Trust chief executives, February 2014, Public Health England/NHS England.
(3) Patient safety alert on addressing rising trends and outbreaks in carbapenemase-producing Enterobacteriaceae, NHS England Patient Safety Alert, March 2014.
(4) Universal admission screening for CRE using PCR detects 14-fold more carriers than agar-based methods at a London Hospital. J Otter et al. Paper Poster presented to ECCMID 2015.