Known as “nightmare bacteria,” cases of drug-resistant infections are alarmingly on the rise in the United States. A recent report from the Centers for Disease Control and Prevention (CDC) reveals that infection rates from these resistant bacteria have surged by almost 70% between 2019 and 2023. The primary driver of this increase is bacteria that possess the NDM gene, which makes them difficult to treat, as highlighted by CDC researchers in an article published in the Annals of Internal Medicine.
According to researchers, only two antibiotics are effective against infections caused by bacteria with the NDM gene. These antibiotics are not only expensive but also require intravenous (IV) administration. Once considered rare and largely linked to patients who received medical care abroad, infections caused by bacteria with the NDM gene have now seen a more than fivefold increase in the U.S. over recent years. “The rise of NDMs in the U.S. is a grave danger and very worrisome,” stated David Weiss, an infectious diseases researcher at Emory University, in an email.
The CDC scientists caution that many individuals may be unrecognized carriers of these drug-resistant bacteria, raising the risk of community spread. This situation could significantly impact healthcare settings across the country, where infections once considered routine, such as urinary tract infections, may become harder to treat. Dr. Maroya Walters, one of the report's authors, emphasized the potential consequences of antimicrobial resistance on everyday medical care.
Antimicrobial resistance occurs when germs, including bacteria and fungi, develop the ability to resist the effects of drugs designed to eliminate them. A significant factor contributing to this rise is the misuse of antibiotics, with incomplete or unnecessary prescriptions allowing germs to become stronger. In recent years, the CDC has highlighted the emergence of “nightmare bacteria” that are resistant to a broad spectrum of antibiotics, particularly carbapenems, which are often viewed as a last resort for treating severe infections.
Data collected from 29 states that conduct necessary testing and reporting of carbapenem-resistant bacteria revealed a troubling trend. In 2023, there were 4,341 cases of carbapenem-resistant bacterial infections reported, with 1,831 cases being of the NDM variety. The incidence rate of carbapenem-resistant infections increased from just under 2 per 100,000 people in 2019 to over 3 per 100,000 in 2023, marking a 69% increase. The rate of NDM cases, however, skyrocketed from approximately 0.25 to about 1.35 per 100,000 people, reflecting a staggering 460% increase.
Experts believe that the rise in drug-resistant infections is partly linked to the COVID-19 pandemic. Dr. Jason Burnham, a researcher at Washington University, noted, “We know that there was a huge surge in antibiotic use during the pandemic, so this likely is reflected in increasing drug resistance.”
It is important to note that the CDC’s data may only represent a fraction of the true situation. Many states lack comprehensive testing and reporting protocols for drug-resistant infections. In states that do report, cases are often confined to hospital patients who are sufficiently ill to warrant specialized testing. Furthermore, numerous hospitals lack the capability to conduct the necessary testing to identify certain forms of genetic resistance. Notably, the CDC researchers did not have data from some of the largest states, including California, Florida, New York, and Texas, which suggests that the actual number of infections in the U.S. is likely much higher than reported.
This is not the first study to document the rise of nightmare bacteria. A CDC report released in June indicated an increase in NDM cases specifically in New York City between 2019 and 2024.
This article was first published on September 23, 2025, and was subsequently updated on September 24, 2025, to clarify that Dr. Walters indicated routine infections could become more challenging to treat rather than transform into a chronic issue.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. However, it is important to note that the AP is solely responsible for all content presented in this article.
