CRE: Carbapenem-Resistant Bacteria — Risks, Spread and Prevention

Enterobacterales are a large group of bacteria that normally live in the gut of people and animals but can also cause infections. Carbapenem-resistant Enterobacterales (CRE) are members of that group that have become resistant to one or more carbapenems — antibiotics often used to treat bacterial infections that resist many other drugs.

In the United States in 2020, CRE caused approximately 12,700 infections and more than 1,100 deaths.

Image from CDC’s page.

Which germs

Familiar bacteria such as Escherichia coli (E. coli) and Klebsiella pneumoniae count as CRE once they become resistant to carbapenems.

One type is especially worrying: NDM-CRE, which produce an enzyme called New Delhi metallo-β-lactamase. Their infections are extremely hard to treat, and they are spreading fast in the United States — up 461% between 2019 and 2023.

What infections they cause

• pneumonia
• bloodstream infections
• urinary tract infections
• wound infections
• meningitis

Who is at risk

Healthy people rarely get CRE infections. The risk is highest for patients in health care settings, especially those who:

• need devices such as ventilators, urinary catheters or intravenous catheters
• are on long courses of certain antibiotics
• have weakened immune systems

How CRE spread

• from person to person, through unclean hands, wounds or stool
• through contaminated medical equipment and devices
• in a few reported cases, between animals and people, and between animals

People and animals can also carry CRE on or in their bodies without being sick — called colonization. Colonized patients often need no treatment.

Treatment

CRE infections are hard to treat because they resist most antibiotics, including the carbapenems themselves. Doctors decide on treatment case by case. If you are prescribed antibiotics, take them exactly as directed and finish the course, even once you feel better.

Lowering your risk

• Take antibiotics only as your health care provider recommends.
• Follow patient-safety advice when you are in a hospital or clinic.
• Keep your hands clean.

Pets and other animals

Animals can pick up CRE from colonized people or other animals. The chance of a pet passing CRE to its owner is low. Scientists are still studying how long animals carry the germs; it may be longer if they keep being exposed or are given antibiotics. If your pet has had CRE, talk to your veterinarian.

What CDC does

• tests for resistance, measures it and tracks how it spreads in health care settings through its Antimicrobial Resistance Laboratory Network
• tracks CRE infections through the Emerging Infections Program and the National Healthcare Safety Network, with data on its AR & Patient Safety Portal
• works with health departments, other federal agencies, health care providers and patients to prevent CRE infections and slow the spread of resistant germs

Sources

Based on "About Carbapenem-resistant Enterobacterales (CRE)," Centers for Disease Control and Prevention; a work of the United States government in the public domain. Image from the same CDC page.