C. diff infection

Infections. Also called: Clostridioides difficile infection, C. difficile.

How common is C. diff infection in the US?

Estimated total national annual burden of Clostridioides difficile infection (unadjusted for NAAT-testing use), 2017: 462,100 cases (US population, annual cases (2017 estimate); United States (CDC Emerging Infections Program surveillance in 10 states, extrapolated to national estimate via sampling weights), 2017 (trend period 2011-2017)). Source: New England Journal of Medicine (CDC), 2020. Label: MODELED.

• 462,100 cases Estimated total national annual burden of Clostridioides difficile infection (unadjusted for NAAT-testing use), 2017. Out of: US population, annual cases (2017 estimate). Where: United States (CDC Emerging Infections Program surveillance in 10 states, extrapolated to national estimate via sampling weights). When: 2017 (trend period 2011-2017). Label: MODELED.

  Without adjustment for NAAT use, the estimated total national burden ofinfection was 476,400 cases (95% CI, 419,900 to 532,900) in 2011, with an estimated incidence of 154.9 (95% CI, 136.5 to 173.3) per 100,000 population, and 462,100 cases (95% CI, 428,600 to 495,600) in 2017, with an estimated incidence of 143.6 (95% CI, 133.2 to 154.0) per 100,000 population ().

  Source: Trends in U.S. Burden of Clostridioides difficile Infection and Outcomes New England Journal of Medicine (CDC), 2020. PubMed 32242357. DOI 10.1056/NEJMoa1910215.

Each figure measures something different. Do not compare them with each other or with other conditions.

Medical codes

• ICD-10-CM FY2026: A04.72 Enterocolitis due to Clostridium difficile, not specified as recurrent (narrower). The code set still uses the older genus name. Recurrent infection has its own code.

Research activity

As of 2026-09-24: 303 registered studies on ClinicalTrials.gov (search Clostridioides difficile Infection) and 5,304 PubMed records, 2021 to 2025. A count of records is not how common or serious the condition is.

Population information, not medical advice. Methodology · Known limitations