Antimicrobial Resistance Associated with Mass Gatherings: A Systematic Review.

Mass gatherings are associated with the spread of communicable diseases. Some studies have suggested that acquisition of antimicrobial resistance (AMR) may be associated with attendance at specific mass gatherings. This systematic review aimed to synthesise evidence on the association between attendance at mass gatherings and antimicrobial resistance (AMR) and assess the prevalence of AMR at mass gatherings. A literature search of the Cochrane, Medline, Scopus, and Embase databases was performed. Studies were included if they reported original data, involved mass gatherings, and reported AMR results. Of 5559 titles screened, 44 studies met the inclusion criteria, most of which (n = 40) involved religious mass gatherings. The heterogeneity of the studies precluded a meta-analysis, hence a narrative synthesis by organism was conducted. A significant increase in antibiotic-resistant Escherichia coli and Klebsiella pneumoniae was reported following Hajj, as was a rise in gastrointestinal carriage of extended-spectrum β-lactamase (ESBL) or carbapenemase genes. Carriage of Streptococcus pneumoniae isolates non-susceptible to one or more antibiotics was also shown to increase from pre-Hajj to post-Hajj. There appears to be an association between attendance at mass gatherings and the acquisition of some AMR phenotypes and genotypes in some significant human pathogens, including E. coli and S. pneumoniae.