Prevalence of Carbapenemase Producing Organisms in East London, UK

Carbapenemases are enzymes, produced by an array of common Gram-negative organisms, which hydrolyse the carbapenem antibiotics, conferring resistance. The main protagonists are the “big five” carbapenemases, KPC, OXA-48, IMP, VIM and NDM, which have been reported across the UK. Rates of carbapenemase producing organisms (CPOs) have risen over the past decade, with many hospitals in the UK reporting related outbreaks. However, these reports are often a result of reactive screening, outbreaks, inpatient surveillance and from diagnostic samples. A point prevalence study (PPS) together with community screening was performed to determine the rate of carriage for our patient population. To date there have been no other community studies performed in the UK. Objectives To determine the prevalence of CPOs within the community serving Barts Health Trust (BHT): Screen 200 non-duplicate samples from the community together with all in-patients at BHT. Results In-patient The prevalence of CPOs across all sites of BHT demonstrates NDM to be the most frequently detected, followed by OXA-48-like carbapenemases. The overall prevalence at 3.1% is in line with data published from other hospital trusts in London. Risk factor information demonstrated patients on renal and care of the elderly wards to be at the highest risk of carbapenemase carriage. No association with foreign travel or hospitalisation abroad was noted. Community A total of 22/46 of our study patients who listed foreign travel visited these high risk counties in the last 12 months. However, only one CPO was detected in our community. Furthermore, the CPO was detected in a patient who had travelled to the Caribbean, not currently listed by PHE as one of these high-risk counties. CPO prevalence studies often focus on critical patient groups such as ITU. However, we found renal patients and those on care of the elderly wards to be at greatest risk of CPO carriage. The community study indicates that risk could be determined by more than just travel to, or birth in, a particular country and that the list of high-risk countries included in UK guidelines may need updating. Currently at BHT no specific patient groups are screened for CPOs. Therefore, it is important to establish which patients need to be investigated for CPOs based on BHT’s own patient population, local CPO prevalence and at-risk patient groups to prevent carriage becoming an infection and to prevent outbreaks.