Differences in the distribution of pathogens and antimicrobial resistance in bloodstream infections in migrants compared with non-migrants in Denmark

BACKGROUND: We wish to study disparities in bloodstream infections in migrants and non-migrants by comparing the distribution of pathogens and their resistance patterns in long-term migrants with that in non-migrants in Denmark.

METHODS: The study is based on a cohort of migrants, who received residency in Denmark between 1993 and 2015 and a control group of non-migrants. The cohort was linked to a database of bloodstream infections from 2000 to 2015 covering two regions in Denmark. First-time bloodstream infections in individuals ≥18 years of age at the time of sampling were included. We calculated odds ratios adjusted for age, sex, year of sampling, comorbidity, and place of acquisition (hospital- or community-acquired).

RESULTS: We identified 4,703 bloodstream infection cases. Family-reunified migrants and refugees had higher odds of Escherichia coli than non-migrants (OR 1.89 95%CI: 1.46-2.44 and OR 1.55 95%CI: 1.25-1.92) and lower odds of Streptococcus pneumoniae (OR 0.38 95%CI: 0.21-0.67 and OR 0.52 95%CI: 0.34-0.81). Differences in pathogen distribution were only prevalent in community-acquired bloodstream infections. Refugees had higher odds of Escherichia coli resistant to piperacillin-tazobactam, ciprofloxacin, and gentamicin compared with non-migrants. Family-reunified migrants had higher odds of Escherichia coli and other Enterobacterales resistant to ciprofloxacin.

CONCLUSIONS: Migrants had a higher proportion of community-acquired bloodstream infections with Escherichia coli as well as higher odds of bloodstream infections with resistant Escherichia coli compared with non-migrants. These novel results are relevant for improving migrant health by focussing on preventing and treating infections especially with Escherichia coli such as urinary tract and abdominal infections.