Risk factors for acquisition of multidrug-resistant Enterobacterales among international travellers: a synthesis of cumulative evidence.

BACKGROUND: Recent studies have shown that over 50% of people travelling to Southeast Asia return colonized with multidrug-resistant Enterobacterales (MRE) including carbapenemase-producing Enterobacterales. Importation of MRE by travellers and subsequent spread to family members, communities and healthcare facilities poses real risks that have not yet been adequately assessed. This systematic review and meta-analysis aims to quantify the risk factors and interventions for reducing the risk of MRE acquisition among international travellers. METHODS: A systematic search was conducted in PubMed, Web of Science and Scopus for analytical epidemiological studies containing data post-2000 that assessed the risk factors to acquire and/or interventions to reduce the risk of MRE acquisition in travellers. Two researchers independently screened all the studies and extracted the information, and disagreements were resolved through consensus. The proportions of MRE acquisition by the region of destination and the odds ratio (OR) for the different risk factors and/or interventions were pooled using the inverse variance heterogeneity model. RESULTS: A total of 20 studies (5253 travellers from high-income countries) were included in the meta-analysis. South Asia [58.7%; 95% confidence interval (CI), 44.5-72.5%] and Northern Africa (43.9%; 95% CI 37.6-50.3%) were the travel destinations with the highest proportion of MRE acquisition. Inflammatory bowel disease (OR 2.1; 95% CI 1.2-3.8), use of antibiotics (OR 2.4; 95% CI 1.9-3.0), traveller's diarrhoea (OR 1.7; 95% CI 1.3-2.3) and contact with the healthcare system overseas (OR 1.5; 95% CI 1.1-2.2) were associated with MRE colonization. Vegetarians (OR 1.4; 95% CI 1.0-2.0) and backpackers (OR 1.5; 95% CI 1.2-1.8) were also at increased odds of MRE colonization. Few studies (n = 6) investigated preventive measures and found that consuming only bottled water/beverages, meticulous hand hygiene and probiotics had no protective effect on MRE colonization. CONCLUSIONS: International travel is an important driver for MRE spread worldwide. Future research needs to identify effective interventions to reduce the risk of MRE acquisition as well as design strategies to reduce local transmission on return.