Hospitals are facing a new wave of trouble from a germ that’s hard to stop. Infections caused by NDM-producing carbapenem-resistant Enterobacterales (CRE) – bacteria that shrug off some of our most powerful antibiotics – have exploded in recent years.
A new peer-reviewed study shows just how steep the climb has been, with cases jumping more than 460 percent between 2019 and 2023.
In 2020, the Centers for Disease Control and Prevention (CDC) estimated about 12,700 CRE infections and 1,100 deaths in the United States. That was a warning sign foreshadowing the spike that is now coming into focus.
Hospital infections on the rise
The latest analysis comes from Danielle Rankin and her team in the Division of Healthcare Quality Promotion. The group tracks resistant germs through national surveillance and public health laboratories.
NDM-CRE belongs to carbapenem-resistant Enterobacterales (CRE), a family of gut bacteria that have learned to defeat carbapenem antibiotics. NDM stands for New Delhi metallo-beta-lactamase, an enzyme that shuts down many beta-lactam drugs at once.
Doctors also see other enzymes called carbapenemases (KPC), but NDM is especially tough. Many antibiotics that work against KPC enzymes do not touch NDM producers.
These resistance genes often sit on plasmids, small DNA loops that jump between bacteria. That trait lets the problem spread across different species and hospitals.
The risks that patients now face
These infections are not just inconvenient. A recent narrative review reports mortality estimates for CRE infections ranging from roughly 26 percent to 44 percent across clinical studies.
“This sharp rise in NDM-CRE means we face a growing threat that limits our ability to treat some of the most serious bacterial infections,” said Rankin.
“Selecting the right treatment has never been more complicated, so it is vitally important that healthcare providers have access to testing to help them select the proper targeted therapies.”
NDM producers cause pneumonia, bloodstream infections, urinary tract infections, and wound infections that can escalate quickly. The stakes are highest for intensive care patients, transplant recipients, and people with long hospital stays.
Many clinical labs still cannot identify the exact carbapenemase behind a resistant isolate. That gap delays the right therapy and gives the organism time to move from ward to ward.
How hospitals detect infections
When a culture grows a resistant Enterobacterales, the next step is to determine the resistance mechanism. If a hospital lab cannot run carbapenemase testing, the CDC’s AR Lab Network can perform testing through public health labs.
Labs use phenotypic assays to check for carbapenemase activity and molecular tests to confirm the gene. Rapid tests help infection control teams act fast to isolate patients when needed.
Confirming the enzyme matters because treatment hinges on the mechanism. It also helps hospitals spot clusters and alert partner facilities when patients are transferred.
Delayed identification lets a single silent carrier seed new cases. The right test at the right time changes the trajectory for a patient and a unit.
Few drugs still work
NDM producers resist nearly all beta lactams, including many newer drugs that work for KPC producers. Current expert guidance recommends cefiderocol or pairing aztreonam with ceftazidime avibactam for metallo beta lactamase producers.
These are intravenous treatments that require careful dosing and close monitoring. They are not options for every infection or every patient.
Combination therapy with aztreonam and ceftazidime avibactam must be given in a coordinated way. The goal is to protect aztreonam from other enzymes while neutralizing the metallo beta lactamase.
Clinicians should involve infectious disease specialists when these organisms are suspected. Empiric therapy should be reassessed promptly once the mechanism is confirmed.
Stopping infections requires basics
The core tools still work when used consistently. CDC infection control guidance calls for Contact Precautions in acute care and Enhanced Barrier Precautions in long-term care for affected patients.
Hand hygiene, dedicated equipment, and environmental cleaning are non-negotiable. Transfers between facilities should include a clear handoff about any history of CRE.
Patients and families can help by asking whether testing has identified the mechanism. They can also remind teams about gowns and gloves if contact with wounds or devices is planned.
Prudent antibiotic use matters too, since unnecessary exposure can select for resistant strains. Stewardship programs and lab capacity go hand in hand to reduce harm.
Where the fight heads next
Hospitals will need broader screening during infections and faster confirmatory testing. Researchers are watching whether NDM expands beyond health care into the community as testing improves.
Public health labs can surge support for facilities that lack capacity. Regional data also guide where to deploy resources and when to coordinate responses across networks.
Health systems will need contingency plans for shortages of key drugs. They will also track outcomes as newer agents enter practice and as resistance shifts again.
The aim is simple: reduce infections, shorten hospital stays, and save lives. That path runs through smart diagnostics, careful therapy, and steady infection control.
The study is published in the journal Annals of Internal Medicine.
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