The U.S. Centers for Disease Control and Prevention (CDC) is warning of a growing public health threat: drug-resistant “nightmare bacteria.” According to a new CDC study, infections by these bacteria have climbed sharply in recent years, potentially putting more people at risk of cases that are difficult or impossible to treat.
Between 2019 and 2023, the rate of carbapenem-resistant bacterial infections often called “nightmare bacteria” because they resist many antibiotics rose by nearly 70 percent in the 29 states that report the detailed genetic tests needed to detect them. Within that group, bacteria carrying the NDM gene (New Delhi metallo-beta-lactamase) showed the steepest rise increasing about 460 percent over the same period.
These NDM bacteria were once rare in the U.S., mostly linked to patients who had received medical care abroad. But now, U.S. cases are multiplying. Only two antibiotics are currently effective against them; both must be given intravenously and come at high cost.
Experts say the rise is alarming. Dr. David Weiss, an infectious-disease researcher, called the increase “a grave danger.” The CDC scientists also warn that many infected people may carry the bacteria without showing symptoms, which could allow it to spread in communities undetected.
That means common infections like urinary tract infections might become harder to treat if they involve these resistant strains.
Misuse of antibiotics (for example, taking them unnecessarily, or stopping them early) is believed to have helped drive the rise of drug resistance.
The CDC’s analysis only includes data from states that do advanced testing, and some of the nation’s most populous states such as California, Florida, New York, and Texas are not fully represented. That suggests the true number of cases may be substantially higher. Data indicate that in 2023 alone, there were 4,341 recorded cases of carbapenem-resistant bacterial infection in those reporting states; 1,831 of them were the NDM type.
Given the sharp increase, public health officials are urging more surveillance, better antibiotic stewardship, stronger infection control in hospitals, and accelerated research into new drugs. The warning from the CDC is clear: without action, these hard-to-treat infections could become more widespread and harder to contain.
