Pathogen distribution and antimicrobial resistance in infections in migrants and nonmigrants in Denmark, a cross-sectional study

Objective: To investigate differences in bacterial distribution and resistance patterns of relevant pathogens in skin and tissue infections among migrants compared to nonmigrants.

Methods: The population is based on a cohort of migrants who obtained residence as refugees or family-reunited migrants in Denmark between January 1993 and December 2015. The cohort was linked to positive swabs and tissue cultures collected from hospitals and general practitioners between the years 2000 and 2016 at the Department of Microbiology, University Hospital Hvidovre, Denmark. We calculated odds ratios for pathogen distribution and resistance patterns using logistic regression by comparing migrants with nonmigrants.

Results: In total, 43,770 pathogens from 37,276 individuals were included, with Staphylococcus aureus being the most common bacterium. Migrants had higher odds of infections with Enterobacterales than nonmigrants (OR 1.42, 95% CI: 1.23-1.63) and lower odds of beta-haemolytic Streptococci (OR 0.79, 95% CI: 0.73-0.86). Family-reunited migrants and refugees had higher odds of methicillin-resistant S. aureus (MRSA) than nonmigrants (OR 5.01, 95% CI: 3.73-6.73 and OR 3.66, 95% CI: 2.61-5.13). This was more pronounced in female migrants. The odds of ciprofloxacin-resistant Enterobacterales were higher in both family-reunited migrants and refugees than in nonmigrants (OR 2.21, 95% CI: 1.34-3.64 and OR 2.17, 95% CI: 1.34-3.52).

Conclusions: The prevalence of MRSA and ciprofloxacin-resistant Enterobacterales was higher among family-reunited migrants and refugees than in nonmigrants. Our findings suggest an increased awareness for AMR in migrants.