Rising Incidence of New Delhi Metallo-β-Lactamase-Producing Carbapenem-Resistant Enterobacterales, 10 US Sites,...

We described the changing epidemiology of New Delhi metallo-β-lactamase (NDM)-producing carbapenem-resistant Enterobacterales (CRE) in 10 US sites conducting population-based CRE surveillance during 2018-2023.

A CRE case was defined as the first isolation of Escherichia coli, Enterobacter spp., or Klebsiella spp. resistant to ≥1 carbapenem from a sterile site or urine in a surveillance area resident within a 30-day period. Cases were classified as healthcare-associated or community-associated. Incidence rates were calculated using census data; trends were assessed using the Mann-Kendall test. Multivariable logistic regression was used to compare NDM- and Klebsiella pneumoniae carbapenemase-producing (KPC)-CRE. A subset of isolates underwent whole-genome sequencing.

During 2018-2023, CRE incidence increased from 5.34 to 7.65 per 100 000 population (P = .02). NDM-CRE incidence increased from 0.07 to 0.66 per 100 000 population (P = .02); no significant trend was observed for KPC-CRE. Odds of being an NDM-CRE case were increased for community-associated versus healthcare-associated cases (adjusted odds ratio [aOR], 3.2; 95% CI, 1.98-5.17) and for cases aged 0-24 years versus ≥75 years (aOR, 3.99; 95% CI, 1.59-10.02). Genomic analysis showed diversity of sequence types among NDM- versus KPC-CRE.

Increases in CRE incidence appear to be driven by NDM-CRE, which are more likely than KPC-CRE to be community-associated. Continued surveillance is recommended to understand changes in epidemiology.