OBJECTIVES : We aimed at conducting an updated systematic review of international scientific evidence in order to analyse whether there was a relationship between bacterial drug resistance and international migration status compared to locals.

METHODS : We searched in PubMed database and included all types of observational studies based on study´s keywords and included manuscripts written in English/Spanish/Portuguese/French/Dutch/German languages. Two independent members (BC, AP) evaluated titles and abstracts and included them when: (i) original research study; (ii) compared international migrants to locals; (iii) looked at bacterial drug resistance. We excluded papers focused on HIV and tuberculosis resistance. When discrepancies were found, a third part (SA) was included for final decision. AHand-search of relevant references from all selected full-text papers was also conducted. Whenever full-texts were unavailable, we contacted authors at least three times. We used Prisma flow chart to describe the study selection process. Data extraction was conducted by one trained researcher (MPA). We conducted a detailed quality assessment of each selected study, based on STROBE and MMAT-Version 2011 checklists. Given the great heterogeneity between studies, we conducted a narrative descriptive synthesis.

RESULTS : Search retrieved 334 hits. Of these, 10 articles met our inclusion criteria (refugees=5, general/not reported=5). 9/10 showed migrants had higher rates of bacterial drug resistance and 1 reported similar rates. From those nine, 5 were focused on refugees living in poverty and with a number of health risks before and after arrival to the host country. Studies showed several methodological limitations.

CONCLUSIONS : According to existing evidence, having a refugee status is associated with higher bacterial drug resistance. High-quality studies are required to explore how vulnerable migrants might face higher risks for bacterial drug resistance compared to general migrant population and locals.