Travel‑associated carbapenem‑resistant organisms at a time of increasing geopolitical instability

Ahead of next week’s IPC Partners journal club (which you can register for here), I have taken a look at the paper at the centre of Dr Luke Moore’s journal club session. You can read the full article in Journal of Hospital Infection here.

I have often been interested in the links between travel and the transmission of infections, right from coughing and sneezing on planes to dreaded Deli belly! In the past decade there has been an increased interest in the epidemiology of Carbapenemase-producing Enterobacterales (CPE) in European countries, with significantly increasing national trends in carbapenem resistance percentages in several European Countries (ECDC). Studies have demonstrated an increased risk of acquiring multidrug-resistant Enterobacterales depending on travel destination and if antibiotics are used during travel.

Recent shifts in global geopolitical stability with increases in conflict and catastrophe present a challenge to UK health security from travel-associated antimicrobial resistance (AMR). Conflict and humanitarian crises disrupt sanitation, healthcare delivery and antimicrobial stewardship, creating environments that favour acquisition and spread of antimicrobial resistance.

The study

Following a meeting to discuss the increasing AMR associated with conflict-associated infections in Europe, the authors invited participants with an interest in conflict-associated AMR to complete a survey which balanced questions on carbapenem-resistant (CRO) screening practices and time burden for completion to optimise representative feedback. The study aimed to characterise how UK centres identify and manage travel‑associated CROs and to describe the molecular patterns of carbapenemase-producing organsims (CPOs) detected in major trauma networks during a period of rising geopolitical instability.

Survey: A short questionnaire sent to microbiology/IPC leads across 108 UK acute Trusts/Boards; 73 responses returned.

CPO data review: Twelve major trauma network laboratories contributed anonymised CPO detections (April 2022–April 2024). Electronic records were reviewed for travel in the preceding six months; organism, sample type and carbapenemase genes were recorded and pooled.

Key findings

• Wide survey coverage with variable practice: 73 of 108 UK acute Trusts/Boards responded; screening approaches and local modifications to national guidance varied across centres.
• Travel‑linked CPO detections are common: Among 1,290 positive CPO results from 12 major trauma centres, 297 (23.0%) had evidence of travel in the preceding six months to 52 countries.
• Most travel‑associated positives were identified by screening: 227 of 297 (76.4%) travel‑associated CPOs were from screening samples (stool/rectal swab); the remainder were clinical isolates.
• Enterobacterales dominate: ~94% of single‑organism travel‑associated detections were Enterobacterales (predominantly E. coli and Klebsiella spp.).
• NDM is the most frequent carbapenemase; diversity varies by region: NDM alone accounted for the largest single group (45.1% of travel‑associated CPOs); carbapenemase diversity was significantly greater among travellers to Europe.
• Operational gaps in travel recording and IPC notification: Recording of travel risk was often retrospective and inconsistent; only ~41% of centres had a mechanism to inform IPC when travel risk was identified.

Limitations

• Retrospective/incomplete travel data: Travel was often identified after a positive result, limiting causal inference
• Selection bias: Use of major trauma centres to capture repatriated patients may not reflect other hospital populations.
• Confounding factors: Other risks (antibiotic exposure, age, length of stay, chronic disease) affect colonisation and complicate attribution to travel.
• Limited molecular scope: Focus on the “big five” carbapenemase families could miss rarer or novel resistance mechanisms.
• Variable local practice: Differences in screening, recording and result‑reporting across sites reduce comparability and may introduce bias

Implications for IPC

In the UK, almost a third of centres had recent experience of detecting CROs associated with recent travel to conflict areas and and present an evolving risk to hospital IPC, and that inconsistent capture of travel history undermines timely, proportionate responses.

For infection control teams this translates into three linked priorities:

• First, ensure travel history is treated as a core epidemiological variable at first contact so that potential importation is identified before onward exposure occurs.
• Second, align operational pathways so that a positive travel history triggers clear, pre‑agreed actions (timely screening, communication to IPC and microbiology, and risk‑based isolation where feasible) rather than ad hoc decisions made after a positive result is found.
• Third, ensure laboratory and reporting pathways are configured to detect the major carbapenemase families and to communicate complex or mixed carbapenemase results rapidly to clinical teams.

Together these measures shift the response from retrospective case finding to proactive risk stratification, reducing the chance of unrecognised introduction and onward transmission while allowing IPC resources to be targeted where they are most needed. A practical shift that can materially reduce the risk of unrecognised CPO introduction and onward spread.