Temporal, regional, and demographic differences among antimicrobial-resistant domestic Campylobacter jejuni human infections across the United States, 2013–2019

Human infections with antimicrobial-resistant Campylobacter jejuni increase morbidity, mortality, hospitalization, and treatment costs. Resistance to antimicrobials recommended to treat campylobacteriosis has increased in the United States, despite the mitigating efforts of public health authorities. This study analyzed publicly available antimicrobial resistance (AMR) monitoring data collected by the National Antimicrobial Resistance Monitoring System (NARMS) to assess temporal, regional, and demographic differences in AMR among domestically acquired C. jejuni infections across the United States between 2013 and 2019. Mann-Kendall tests evaluated trends in AMR throughout the study period. Poisson regression models assessed differences in resistance to each antimicrobial class among the years, age groups, and regions. Among the 7624 C. jejuni isolates, high resistance was identified against tetracyclines (n = 3504; 45.96%; 95% CI = 44.84-47.09), and quinolones (n = 2093; 27.45%; 95% CI = 26.45-28.47). An increasing trend in resistance to quinolones (P = 0.07) and a decreasing trend for tetracyclines (P = 0.036) were identified. The rate of isolates that showed resistance to all antimicrobial classes except tetracyclines was significantly higher in the state of Connecticut. Resistance rates for all antimicrobials except aminoglycosides were higher among the 20-39 year age group. Regions and age groups with the greatest AMR rates were identified, which warrants further studies to identify individual and area-level risk factors. To mitigate the burden of antimicrobial-resistant C. jejuni infections, health authorities should focus on regions and age groups with the highest risk.