Extended-spectrum cephalosporin-resistant Enterobacterales

Threat Level: SERIOUS

In the United States in 2023:

CDC changed methodologies and data sources to produce the most comprehensive AR Threats Report to date. Direct comparison of this threat's data to previous reports is not recommended.

What you need to know

Enterobacterales are a group of bacteria that live in the intestines of people and animals. Although some of these bacteria normally live in our bodies without causing problems, they can cause infections in the urinary tract, blood, and other parts of the body. Common Enterobacterales include Escherichia coli (E. coli) and Klebsiella species.

Some Enterobacterales are resistant to a group of antibiotics known as extended-spectrum cephalosporins, which are widely prescribed to treat many different types of infections. Some extended-spectrum cephalosporin-resistant Enterobacterales (ESC-RE) produce enzymes that enable the bacteria to destroy these antibiotics and are known as extended-spectrum β-lactamase (ESBL)-producing Enterobacterales.

About half of ESC-RE infections occur in people who have not had recent health care. Even common infections, such as urinary tract infections, caused by ESC-RE may require more complex treatments, such as intravenous carbapenem antibiotics, and may not be treatable with oral antibiotics. The more we rely on carbapenem antibiotics, the greater the possibility of resistance developing to this important class of antibiotics.

Extended-spectrum cephalosporin-resistant Enterobacterales data

In 2023, there were an estimated 293,299 cases of extended-spectrum cephalosporin-resistant Enterobacterales (ESC-RE) in hospitalized patients and 13,886 people who died due to their ESC-RE infection. CDC estimates that ESC-RE cases were responsible for more than $2.29 billion in healthcare costs in 2023. Preventing ESC-RE infections is critically important since they can be difficult to treat.

Previous Antimicrobial Resistance Threats Reports (AR Threats Reports) shared information about extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, which included extended-spectrum cephalosporin-resistant Escherichia coli (E. coli) and Klebsiella species, except Klebsiella aerogenes (K. aerogenes). Starting in 2026, the AR Threats Report includes additional Enterobacterales (Enterobacter species and K. aerogenes), and the name of this pathogen group has been updated to extended-spectrum cephalosporin-resistant Enterobacterales (ESC-RE) to reflect these broader inclusions. This provides a more comprehensive picture of resistance and burden in the United States.

Number of extended-spectrum cephalosporin-resistant Enterobacterales (ESC-RE) cases in hospitalized patients (N=293,299) by location of onset and specimen type in 2023 in the U.S.

In 2023, 18% of the ESC-RE cases in hospitalized patients were hospital-onset and 82% were community-onset. Hospital-onset cases occur when specimens (samples) taken from patients on or after day four of hospitalization test positive for ESC-RE. Community-onset cases occur when specimens taken from patients immediately before or within the first three days of hospitalization test positive for ESC-RE. Community-onset cases may be in patients with recent healthcare exposure prior to their hospitalization, including nursing home residents.

Twelve percent of hospital-onset ESC-RE cases and 13% of community-onset ESC-RE cases were invasive. Invasive cases mean ESC-RE are found in normally sterile (free from germs) body sites, such as blood or cerebrospinal fluid. Non-invasive cases mean ESC-RE are found in non-sterile sites, such as the urinary tract, the respiratory tract, or wounds.

Most reported ESC-RE cases are non-invasive. Non-invasive infections can be mild or severe, and some non-invasive infections, like pneumonia, can be deadly. Invasive infections are very serious and can be deadly, often resulting in significant healthcare needs, antibiotic use, and an increased risk for sepsis.

For the first time, data from the National Healthcare Safety Network (NHSN) Antimicrobial Use and Resistance Module were used to estimate the burden of ESC-RE as shown in the figure above.

For the figure below, CDC used data from 2012 to 2022 from large electronic health databases to review changes in the rates of patient hospitalizations with common types of ESC-RE: E. coli and Klebsiella species, except K. aerogenes (ESCR-EK).

Incidence rates of patient hospitalizations with extended-spectrum cephalosporin-resistant Escherichia coli and Klebsiella spp. (ESCR-EK) by year and location of onset in the U.S.

A previously published analysis, shown in the figure above, indicates that the estimated rate of hospitalizations with community-onset ESCR-EK cases increased between 2012 and 2022 [1]. The estimated rate of hospitalizations with hospital-onset ESCR-EK increased during 2020 through 2022 compared to 2019, likely for reasons related to the COVID-19 pandemic, including sicker patients with longer hospital stays [2]. The credible intervals (range of values likely to include the true value) overlap for the hospital-onset ESCR-EK yearly estimates during 2019 to 2022, suggesting that assessment of changes from year to year should be made cautiously.

Continuing to track ESC-RE bacteria over time both in and outside of hospitals can guide actions to prevent infections.

Using local resistance data to drive infection prevention practices

Drug-resistant bacteria like ESC-RE use many defense strategies, called resistance mechanisms, to survive. View this fact sheet to learn more.

The New York Emerging Infections Program (NY EIP) tracks bacterial pathogens in Monroe County, including extended-spectrum β-lactamase (ESBL)-producing Enterobacterales, a subset of extended-spectrum cephalosporin-resistant Enterobacterales (ESC-RE).

From 2020 to 2023, the NY EIP observed a 16% increase in new ESBL-producing Enterobacterales infections in Monroe County. Most infections were Escherichia coli (E. coli) urinary tract infections (UTIs) and many occurred in patients with a history of recurrent UTIs. Most occurred in the community setting, with relatively few acquired in the hospital.

The NY EIP quickly shared these findings with local health systems. The surveillance findings and clinical experience showed that many of these patients were seen in urology practices, leading to a quality improvement project to optimize antibiotic use for UTIs in urology practices.

Additionally, the NY EIP studied risk factors for ESBL-producing E. coli UTIs to inform prevention strategies. They found that patients may also have diabetes, previous ESBL-producing Enterobacterales infections, recent healthcare exposure, or antibiotic use. The NY EIP shared these insights with public health partners, emphasizing the importance of reviewing past microbiology results and using antibiotics appropriately across all care settings.

How CDC combats extended-spectrum cephalosporin-resistant Enterobacterales

Tracking infections
CDC monitors and tracks infections through the National Healthcare Safety Network and the Emerging Infections Program to protect patients, guide strategies to prevent healthcare-associated infections (HAIs), and measure progress of HAI prevention actions.
Collaborating through partnerships
CDC works closely with health departments, other federal agencies, healthcare facilities and providers, and patients to prevent ESC-RE infections and stop the spread of resistant bacteria.

Extended-spectrum cephalosporin-resistant Enterobacterales resources

Illustration of Extended-spectrum cephalosporin-resistant Enterobacterales

Data Methods
Learn how CDC analyzed data to develop the information and estimates shared on this page.
About ESBL-producing Enterobacterales
Find out about extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (a subset of ESC-RE) including causes, treatment options, and prevention actions.
Multi-site Gram-negative Surveillance Initiative (MuGSI)
Access annual data reports on ESBL-producing Enterobacterales from MuGSI, a part of the Emerging Infections Program.
Gram Negative | A.R. & Patient Safety Portal
Access data on gram-negative pathogens (including cephalosporin-resistant Escherichia coli and cephalosporin-resistant Klebsiella) from the National Healthcare Safety Network.