Cases of drug-resistant 'nightmare bacteria' have surged by nearly 70% in the United States between 2019 and 2023, according to a new report from the Centers for Disease Control and Prevention (CDC). The increase is primarily driven by bacteria carrying the NDM gene, which makes them resistant to most antibiotics. Only two antibiotics remain effective against these infections, and they are expensive and must be administered intravenously.
Once considered rare and linked to patients who had received medical care abroad, NDM-carrying bacteria have become more common in the US. The rate of such cases jumped more than fivefold in recent years, the researchers reported. 'The rise of NDMs in the US is a grave danger and very worrisome,' said David Weiss, an infectious diseases researcher at Emory University.
The CDC scientists warned that many people may be unrecognized carriers of the drug-resistant bacteria, potentially leading to community spread. This could turn routine infections, such as urinary tract infections, into chronic problems, said Dr. Maroya Walters, one of the report's authors. Antimicrobial resistance occurs when germs gain the power to fight off drugs designed to kill them, often due to misuse of antibiotics.
The study, published in the Annals of Internal Medicine, analysed data from 29 states that test and report carbapenem-resistant bacteria. In 2023, these states reported 4,341 cases of such infections, with 1,831 involving the NDM variety. The rate of carbapenem-resistant infections rose from under 2 per 100,000 people in 2019 to over 3 per 100,000 in 2023—a 69% increase. For NDM cases, the rate jumped from around 0.25 to about 1.35 per 100,000, a 460% increase.
Some experts link the rise to the COVID-19 pandemic. 'We know that there was a huge surge in antibiotic use during the pandemic, so this likely is reflected in increasing drug resistance,' said Dr. Jason Burnham of Washington University. However, many states are not fully testing and reporting cases, and even in those that do, cases tend to be among hospital patients sick enough to warrant special testing. The CDC researchers lacked data from populous states like California, Florida, New York, and Texas, meaning the absolute number of US infections 'is definitely underestimated,' Burnham added.
