Centers for Disease Control and Prevention

Antimicrobial Resistance Threats Report

Clostridioides difficile

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

Clostridioides difficile, or C. diff, bacteria cause diarrhea and colitis (inflammation of the colon). C. diff can spread from person to person in fecal matter (poop) or by touching contaminated surfaces. These bacteria are common in health care and the natural environment. While rare, serious complications of C. diff infections can occur, including toxic megacolon (a severe intestinal condition), sepsis (the body's extreme response to an infection), and even death.

While C. diff infections can affect anyone, they have historically been more common among patients in healthcare settings, such as hospitals and nursing homes. The chances of getting a C. diff infection are higher in people who are taking antibiotics or who took antibiotics in the past three months. Antibiotics treat bacterial infections by killing harmful bacteria, but they may also affect helpful germs and disrupt the balance of the microbiome. The microbiome is the community of germs that live on and in the human body, including on the skin and in the gut. An unbalanced microbiome can allow harmful germs, like C. diff, to overgrow and cause infection.

Although C. diff infections are not typically drug-resistant, C. diff is included in CDC's Antimicrobial Resistance Threats Report because key factors—including antibiotic use and the spread of germs—drive both C. diff infections and the development of antimicrobial resistance, also known as drug resistance.

Clostridioides difficile data

In 2023, Clostridioides difficile (C. diff) caused more than 400,000 estimated cases among hospitalized and non-hospitalized patients, more than 11,000 estimated deaths among hospitalized patients, and more than $6.4 billion in healthcare costs overall.

Previous Antimicrobial Resistance Threats Reports (AR Threats Report) only included hospitalized C. diff cases. This report expands that scope to include both hospitalized and non-hospitalized C. diff cases, offering a more comprehensive picture of C. diff's burden in the United States.

While C. diff was on CDC's urgent threats list in the 2013 and 2019 AR Threats Reports, CDC has measured declines in cases since 2011. Because of successful prevention actions, especially in healthcare settings, C. diff is now categorized as a serious threat. Still, C. diff causes substantial infections, deaths, and healthcare costs in the United States. C. diff remains one of the most common causes of healthcare-associated infections in hospitals, and there is an even greater number of community-associated cases. Continued infection control and appropriate antibiotic use remain important for sustaining progress in reducing C. diff infections. CDC will continue to monitor trends in C. diff burden and the potential for the development of resistance to treatments.

Number of Clostridioides difficile cases by year in the U.S.

The estimated total number of C. diff cases declined by an unadjusted 21% between 2018 to 2020, with decreases in both healthcare- and community-associated cases. A C. diff case is classified as community-associated if the stool specimen (sample) that tested positive for C. diff was collected on an outpatient basis or within three days after hospital admission in a person with no documented overnight stay in a healthcare facility in the previous 12 weeks. All C. diff cases that do not meet these criteria are classified as healthcare-associated.

These decreases were likely related to better infection control and improved antibiotic use in healthcare and community settings. There were also changes in diagnostic testing practices for C. diff infections that may have contributed. Healthcare-associated C. diff cases were relatively stable between 2020 and 2023, while community-associated cases increased slightly. The increase in community-associated cases in 2022 and 2023 might be related to a return to pre-COVID-19 pandemic levels of outpatient healthcare visits.

The estimates were not adjusted for changes in diagnostic testing practices or other factors that occurred. The confidence intervals (range of values likely to include the true value) across all years overlap, except between 2018 and 2020 for all cases and healthcare-associated cases, suggesting that assessment of changes from year to year should be made cautiously.

Number and rate of Clostridioides difficile cases by year and age group in the U.S.

C. diff case counts were similar across age groups from 2018 to 2023. However, people who are 65 years and older have a much higher risk of C. diff infection. Older adults get C. diff infections at 4.5 to 5 times the rate of younger people, despite a 28% decrease in the infection rate among older adults between 2018 and 2020. Older adults and their caregivers should be aware of this risk and take steps to prevent C. diff infection.

Seeing the potential harm of antibiotic overuse clearly

Peggy Lillis Foundation Story

In this video, Christian John Lillis, co-founder and executive director of the Peggy Lillis Foundation, shares his mother's story on C. diff and the deadly risks of antibiotic use.

Antibiotics are a medical marvel of the 20th century, but they can carry risks. Christian John Lillis, co-founder and executive director of the Peggy Lillis Foundation (PLF), shares his family's story about the devastating impact of Clostridioides difficile (C. diff).
Lillis explains, “My mother Peggy was a healthy 56-year-old kindergarten teacher. Following a root canal, her dentist prescribed the antibiotic clindamycin. After four days, she came down with diarrhea. We didn't connect her diarrhea to the antibiotic until her symptoms were so severe that we had to take her to the hospital. Doctors quickly recognized she had toxic megacolon caused by C. diff and was in septic shock.”
Despite the doctors' best efforts, Lillis's mother passed away about a week after her root canal. His family was left stunned and devastated, since treatment of one infection led to a different infection that was fatal. Shortly after, Lillis co-founded PLF with his brother to help increase awareness of C. diff and potential risks associated with antibiotic use. PLF has built a nationwide C. diff awareness movement through education and advocacy.
Lillis notes, “Antibiotics are miracle drugs. They underpin most modern medicine. To avoid unnecessary infections and prolong these drugs' effectiveness, we must first see both the potential harms, as well as benefits, of antibiotics.”

How CDC combats Clostridioides difficile

  • Tracking infections

    Through the National Healthcare Safety Network and the Emerging Infections Program, CDC monitors Clostridioides difficile (C. diff) infections to protect patients, guide strategies to prevent infections, and to measure progress of C. diff prevention actions.

  • Supporting infection prevention efforts

    CDC provides guidelines and recommendations for infection control programs to help prevent the spread of C. diff in healthcare settings.

  • Expanding implementation of antibiotic stewardship programs

    CDC supports improving appropriate use of antibiotics through antibiotic stewardship, including focusing on specific antibiotics linked to C. diff infections.

  • Addressing critical issues

    CDC works to identify and focus on issues associated with C. diff infection. This includes understanding the role of an unbalanced microbiome; the role of people who carry and can spread the bacteria; patterns and rates of disease; and promoting implementation of thorough cleaning and disinfection practices in healthcare settings.

Clostridioides difficile resources

Illustration of Clostridioides difficile