CPE stands for carbapenemase-producing Enterobacteriaceae, a group of gut bacteria that have developed resistance to carbapenems, the strongest antibiotics doctors have. These bacteria are sometimes called “superbugs” because they can shrug off nearly every antibiotic available, making infections extremely difficult to treat. In 2020, carbapenem-resistant Enterobacteriaceae caused roughly 12,700 infections and 1,100 deaths in the United States alone.
How CPE Bacteria Resist Antibiotics
Enterobacteriaceae are a large family of bacteria that naturally live in the human gut. Most are harmless, and some are even helpful. The species most commonly involved in CPE include E. coli (about 42% of cases), Klebsiella species (20%), Enterobacter species (14%), and Citrobacter species (5%).
What makes CPE dangerous is a specific enzyme called carbapenemase. This enzyme breaks apart the molecular structure of carbapenem antibiotics, disabling them before they can kill the bacteria. Because carbapenems are typically reserved as a last resort when other antibiotics fail, bacteria that can neutralize them leave doctors with very few treatment options. Worse, CPE bacteria often carry resistance to multiple other antibiotic classes at the same time.
Carrying CPE vs. Having an Infection
There’s an important distinction between colonization and infection. Most people who pick up CPE are colonized, meaning the bacteria live in their gut without causing any symptoms or harm. In studies of hospital patients screened with rectal swabs, many tested positive for CPE but never developed an actual infection.
An infection, by contrast, occurs when CPE bacteria enter a normally sterile part of the body, like the bloodstream, urinary tract, or cerebrospinal fluid, and trigger symptoms. CPE infections tend to be serious. They’re associated with high rates of complications and death, partly because the usual antibiotics don’t work and partly because the patients who get them are often already critically ill.
Who Is Most at Risk
CPE spreads primarily in healthcare settings: hospitals, long-term care facilities, and rehabilitation centers. The main risk factors are recent hospitalization (especially in a country where CPE is common), recent antibiotic use, and extended stays in intensive care units. Devices like urinary catheters and ventilators also increase risk because they create entry points for bacteria.
International travel is a significant and growing factor. A Finnish study found that patients hospitalized in South Asia picked up CPE at a rate of 14.6%, while those hospitalized in North Africa had a rate of 13.7%. Among individual countries, Egypt (20.8%) and India (16.4%) showed the highest colonization risks. Taking antibiotics while traveling further increased the likelihood of acquiring CPE. Even without hospitalization abroad, spending time in regions where these bacteria circulate widely raises your chances of becoming a carrier.
A Rapidly Growing Threat
CPE is not a stable problem. It’s accelerating. Between 2019 and 2023, infections caused by one particular type of CPE, those producing an enzyme called NDM, surged by more than 460% in the United States. NDM-producing bacteria are resistant to nearly all available antibiotics, making them among the most dangerous drug-resistant organisms in the world. The CDC flagged this rise in a 2025 report as a major public health concern.
How Hospitals Screen for CPE
Because carriers don’t have symptoms, hospitals can’t rely on clinical signs to identify who has CPE. Instead, they use active screening programs. The standard method involves a rectal swab, which is tested in the lab using selective culture media designed to highlight carbapenem-resistant bacteria. If growth appears, further rapid tests identify the specific type of carbapenemase the bacteria produce.
Hospitals typically screen patients who have recently been hospitalized abroad, transferred from another healthcare facility, or had a known exposure to CPE. The goal is to identify carriers before they unknowingly spread the bacteria to other vulnerable patients. Screening results usually come back within one to two days, depending on the lab method used.
Treatment When Antibiotics Fail
Treating a CPE infection is challenging but not impossible. Over the past several years, a wave of newer antibiotics and antibiotic combinations have been approved specifically for carbapenem-resistant infections. These typically pair a traditional antibiotic with a second compound that blocks the carbapenemase enzyme, protecting the antibiotic from being destroyed. Several of these combinations were FDA-approved between 2017 and 2025.
Other newer drugs work through different strategies entirely, like hitching a ride on the bacteria’s own iron-transport system to sneak inside, or belonging to antibiotic classes that carbapenemase enzymes can’t break down. The specific treatment depends on which type of carbapenemase the bacteria produce, which is why lab identification of the enzyme type matters so much. Despite these advances, CPE infections still carry significantly higher mortality than infections caused by susceptible bacteria, and treatment often requires hospitalization and close monitoring.
How CPE Spread Is Controlled
Infection control in healthcare settings relies on a strategy called contact precautions. When a patient is identified as a CPE carrier or has an active infection, they’re placed in a single room whenever possible. Healthcare workers entering the room wear gloves and a gown, which they remove and dispose of before leaving. Hand hygiene before and after every patient interaction is the single most important step in preventing transmission.
Equipment like blood pressure cuffs and stethoscopes are either dedicated to that patient or thoroughly disinfected between uses. The patient’s room gets priority cleaning at least once daily, with extra attention to high-touch surfaces like bed rails, call buttons, and door handles. When the patient needs to be moved for tests or procedures, any colonized or infected areas of the body are covered, and clean protective equipment is used at the destination. These measures sound intensive, and they are. But they’re effective at preventing the bacteria from spreading to other patients who may be more vulnerable to serious infection.