Travel-Related Antimicrobial Resistance: A Systematic Review 2020-2024

Antimicrobial resistance (AMR) has emerged as a significant global public health concern in recent decades and poses a serious threat to the effective prevention and treatment of various infectious diseases. The World Health Organisation (WHO) has declared AMR a "global health security threat" and has called for urgent action to address this pressing issue [1]. One of the key drivers of the global AMR crisis is the interconnected nature of the modern world, where the rapid movement of people, goods, and pathogens across borders has facilitated the spread of resistant microorganisms. International travel has been identified as a significant contributing factor to the dissemination of antimicrobial-resistant pathogens [2,3]. Given the increasing frequency and volume of global travel, the threat of travel-related AMR is particularly concerning. According to the United Nations World Tourism Organisation (UNWTO), international tourist arrivals reached 1.5 billion in 2019, a significant increase from previous decades [4]. This unprecedented level of international mobility has created ample opportunities for the cross-border transmission of antimicrobial-resistant microorganisms, further intensifying the global AMR crisis. The spread of antimicrobial resistance through travel-related pathways poses a significant public health challenge, with far-reaching consequences. Resistant pathogens acquired during travel can be introduced into new geographical regions, leading to the emergence and dissemination of resistant strains in local populations [5]. This can compromise the effectiveness of antimicrobial treatments, making infections more difficult to manage and increasing the risk of adverse health outcomes. Moreover, the burden of travel-related AMR extends beyond individual health. The economic implications are also substantial, as the treatment of resistant infections often requires more costly and complex interventions, leading to increased healthcare expenditures and lost productivity [6]. Global health security implications are also concerning, as the unchecked spread of resistant microorganisms can undermine the ability of countries to respond effectively to infectious disease outbreaks and pandemics [7]. The scale and impact of travel-related AMR are well-documented in the literature. A systematic review published in 2020 found that the prevalence of antimicrobial-resistant gut colonisation among international travellers ranged from 20% to 80%, with higher rates observed in individuals travelling to low- and middle-income countries [8]. Another study reported that travellers returning from the Indian subcontinent had an increased risk of acquiring ESBL-producing Enterobacteriaceae compared with those who did not travel [9]. The consequences of travel-related AMR are also evident in the data. A study conducted in the Netherlands found that nearly one-third of all ESBL-producing E. coli infections in the country were attributable to international travel [10]. Similarly, a report from the European Centre for Disease Prevention and Control (ECDC) estimated that travel-associated infections contribute to approximately 10-20% of all carbapenem-resistant Enterobacteriaceae (CRE) cases in the European Union [11]. Addressing this public health challenge is urgent because of the increasing prevalence and global spread of antimicrobial-resistant pathogens associated with travel. In 2021, a systematic review provided insights into the impact of travel on the dissemination of AMR worldwide [5]. Given the growing recognition of the importance of this issue, there is a need for a comprehensive and up-to-date synthesis of the current literature on travel-related AMR. Therefore, this systematic review aims to synthesise existing evidence on the relationship between travel and the acquisition and transmission of antimicrobial-resistant pathogens, focusing on the period from 2020 to 2024.