Rapid risk assessment: Increase in OXA -244 -producing Escherichia coli in the European Union/European Economic Area and the UK since 2013

Risk assessment

Rapid risk/outbreaks assessment aim at supporting the countries and the European Commission in their preparedness and response to a public health threat. They provide a timely summary and risk assessment of a public health threat for EU/EEA countries related to a specific event. They also include potential options for response. As outbreaks or public health events develop, ECDC may issue updated risk assessments.

Executive summary

Following an urgent inquiry in ECDC’s EPIS AMR-HAI regarding an increasing number of cases of OXA-244-producing Escherichia coli and identification of a cluster of E. coli sequence type (ST) 38 in Germany, national public health reference laboratories in European Union/European Economic Area countries were invited to submit whole genome sequencing (WGS) data to ECDC for a European-level analysis. The pooled European data showed that 33 cases of OXA-244-producing E. coli were detected between 2013 and 2015, followed by 31 cases in 2016, 21 cases in 2017, 83 cases in 2018 and 116 cases in 2019. Increased use of WGS may have enabled more discriminatory identification of cases from sample collections and contributed to the observed increase in cases. The WGS data identified one main, geographically dispersed cluster of E. coli ST38 with chromosomally encoded blaOXA244 present in all countries that had submitted data (Denmark, Finland, France, Germany, Ireland, Luxembourg, the Netherlands, Norway, Sweden and the United Kingdom). Most of the cases in this cluster were detected in 2018 and 2019.

The source and the route of transmission of OXA-244-producing E. coli in the EU/EEA and the UK is currently unclear. An overlap in time and place was identified for a few cases in Germany, indicating possible person-to-person transmission. Healthcare-associated clusters were not observed and transmission in healthcare settings cannot explain the dispersed distribution in ten countries and different regions within countries without linked hospital referral networks.

The observed increase in the number of cases of a difficult-to-detect carbapenemase (OXA-244) in a species (E. coli) that causes community-acquired infections is of concern. The risk of further spread of OXA-244-producing E. coli in the EU/EEA is probably high, given the rapid and simultaneous increase in multiple countries. If awareness, sampling frequency and capacity to detect OXA-244 is improved in clinical microbiology laboratories, and appropriate infection prevention and control measures are implemented on a timely basis, the risk for transmission within healthcare settings will be low. However, without adaptation of microbiological methods and surveillance, OXA-244-producing E. coli may continue to spread unnoticed. There is a risk that transmission of OXA-244-producing E. coli in the community may contribute to the loss of carbapenems as options for treatment of serious E. coli infections in the EU/EEA. Therefore there is an urgent need for further investigation to determine the source and routes of transmission of OXA-244-producing E. coli in the EU/EEA, and implement adequate control measures.

The low genetic diversity of the main cluster could have a number of explanations, including a recently emerging clone, but may also point to a source of OXA-244-producing E. coli that could have been distributed to all ten of the countries involved. Information about travel was available for only a few cases (12%), meaning that it has been impossible to draw conclusions on the importance of travel as a risk factor. Transmission via food (animal or non-animal origin), by contact with the environment or direct contact with animals, is hypothetically possible. However, no OXA-244-producing E. coli isolates from food or animal sources have so far been identified in Europe. Imported food or animal products from regions where OXA-48-like carbapenemases are endemic, or even food from domestic sources can therefore neither be excluded, nor confirmed as a possible contributing factor. However, given the potential public health implications, the possibility of food and animal products contaminated with OXA-244 producing E. coli being distributed over a large geographical area would require investigation. Further studies therefore need to be considered to determine the likelihood of the environment, crops, animals and foods contaminated with OXA-244-producing E. coli having contributed to this outbreak.

Options for response include national alerts to clinical microbiology laboratories, laboratory guidance to improve detection of OXA-244-producing E. coli and submission of all suspected isolates to national reference laboratories for further analysis, combined with prospective collection of epidemiological data on cases and associated risk factors. For further details, please refer to the ‘Options for response’ section below.

Read more on ECDC website

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