The modification of laboratory detection methodology and a quality improvement process to control a Carbapenemase producing organism outbreak

Miss Yvonne Carter1

1The Royal Free London NHS Foundation Trust, London, United Kingdom


Over a two month period, it was noticed that patients transferred from a district hospital to an acute hospital in London were found to be colonised with an OXA-48 Klebsiella pneumonia having previously screened negative. A more sensitive laboratory testing methodology in the acute hospital identified these previously undetected cases of OXA-48 carriage, thus resulting in an ‘outbreak’ scenario. A Quality Improvement (QI) process was implemented to manage the outbreak


Identification of OXA-48 Carbapenemase producing organisms (CPOs) with a more sensitive methodology utilised a reduced Meropenem minimum inhibitory concentration (MIC ≥0.125 mg/L reduced from ≥2 mg/L), consideration of Temocillin resistance and an immune-chromatography assay test. Once additional cases were identified, a multi-disciplinary QI programme was implemented to resolve the outbreak and embed effective screening to prevent further cases.


Over a nine month period 96 patients were identified with OXA-48 CPOs. Using a quality improvement methodology, the outbreak resulting from increase in detected cases was speedily closed. With engagement from senior hospital management and a strong ward-based infection prevention presence, there was a clear culture shift creating a ‘can-do’ attitude to outbreak management.


OXA-48 CPOs can be difficult to identify since Meropenem MICs can be much lower than the accepted clinical breakpoint for resistance and considering additional Temocillin resistance may be a better indicator for OXA48 detection. In addition, a systematic quality improvement process was found to be invaluable in the management of the additional cases detected.


Yvonne is Head of Infection Prevention and Control (IPC) at The Royal Free Hospital London. She gained a BSc honours degree in Nursing Practice, qualified in renal transplant and dialysis nursing and has a BSc in IPC. She is an Honorary Lecturer with University College London. She has worked with The House of Commons research team and consulted at the British Embassy in Japan. Yvonne led the IPC team winning National IPC awards in 2009 and 2014 for managing multi-drug resistant infections and presents at Public Health England conferences. Yvonne was on the working party developing National guidelines for safe protective clothing for high consequence infectious diseases. She lectures and provides IPC expertise in England, Europe and Asia, appointed a Council Member of the 1st Board of Hospital Infection Management of World Federation of Chinese Medicines Societies and is on the editorial board for Annals of Infection (ISSN 2616-2709).

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