The World Health Organization considers antimicrobial resistance (AMR) one of the top global public health threats. This is because AMR in pathogens can make antibiotics ineffective against otherwise easily treatable infections. AMR is complex and our fight against AMR necessitates a multipronged approach. A surveillance system that can provide continuous and reliable AMR data is a cornerstone of our efforts to combat AMR.

The National Antimicrobial Resistance Monitoring System (NARMS) is a national public health surveillance system in which FSIS partners with the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA) and state and local public health departments. Together, NARMS partners track changes in the antimicrobial susceptibility of select foodborne bacteria found in ill people (CDC), retail meats (FDA) and food animals/ animal-derived foods (FSIS). This national surveillance program helps public health agencies continually assess the nature and magnitude of bacterial antimicrobial resistance (AMR) at different points in the farm-to-fork continuum. The NARMS agencies use these data to identify new resistance patterns, track changes over time and understand the impact of interventions designed to limit the spread of resistance.

In calendar year (CY) 2024, NARMS partners summarized the most significant CY 2021 AMR findings in the 2021 NARMS Integrated Report. While the NARMS whole-genome sequence-based predictive AMR interpretations are available in real-time via NARMS Now and through the National Center for Biotechnology Information (NCBI), a comprehensive analysis of these data, after intensive review of the data by NARMS partners, is published in the NARMS Integrated Report (IR). To facilitate comparisons of CY 2021 findings with previous years (CY 2020 and CY 2018-2020 averages) the format of 2021 IR was updated to include improved visualization tools and statistical significance.

Key Salmonella findings from the 2021 report include:

• Most (78%) Salmonella from humans were not resistant to any antimicrobials tested under NARMS. This is consistent with results from 2006 to 2020, where 76%–85% of Salmonella from humans were not resistant to any antimicrobials tested.
• A concerning resistance pattern termed Decreased Susceptibility to Ciprofloxacin (DSC: Resistant + Intermediate resistant categories together) was detected through NARMS surveillance. DSC was found to be increasing in Salmonella.
  • In humans, DSC in Salmonella showed increasing trend (9% in 2020 to 11% in 2021) primarily due to serotypes I 4,[5],12:i:- (9% in 2020 to 19% in 2021) and Enteritidis (29% in 2020 to 32% in 2021).
  • In chicken, DSC in Salmonella increased among all chicken sources except retail chicken.
  • In chicken products, DSC in serotype Enteritidis increased from 20% in 2020 to 29% in 2021.
• Like DSC, a resistance pattern termed Decreased Susceptibility to Azithromycin (DSA) was detected through NARMS surveillance. DSA was detected in less than 2% of Salmonella isolated from humans with serotype Newport comprising the majority (59%) of the isolates.  
• Colistin resistance in Salmonella isolates from most retail and food animal samples was below 3% except for cattle products, where it was detected in 8% of isolates.

FSIS and CDC use NARMS information on a case-by-case basis to investigate foodborne illnesses and outbreaks. FDA also routinely uses NARMS data in its regulatory review and approval of new animal antimicrobial drugs and to develop and update policies on the judicious use of antimicrobials in animals.

People using assistive technology such as a screen reader may not be able to fully access all permutations of the information available in the interactive resistance displays. To gain alternate access to the information you may download the spreadsheets containing source data. People with disabilities who require further assistance may contact NARMS@fda.hhs.gov.