Clostridioides difficile Infection (CDI) Surveillance

Overview

As part of CDC's Emerging Infections Program (EIP) Healthcare-Associated Infections – Community Interface (HAIC) Activity, the Clostridioides difficile infection (CDI) Surveillance Program identifies and monitors:

• CDI incidence and burden in communities and healthcare settings.
• Molecular and microbiologic characteristics of strains causing disease.
• Trends in disease over time, including changes in strain prevalence.

To collect this information, trained professionals conduct active population- and laboratory-based surveillance in 10 EIP sites.

Public health professionals and healthcare administrators can use these data to further research such as:

• Identifying risk factors for CDI.
• Identifying populations to prioritize for vaccines and other prevention measures.
• Monitoring effectiveness of prevention strategies.

Highlights

What the data shows

• There were 116.1 cases per 100,000 persons in EIP sites in 2022.
• Underlying conditions were common among CDI cases.
• 56% of CDI cases used antibiotics in the prior 12 weeks.1

Explore the data

Annual reports

• 2022 Annual Report
• 2021 Annual Report
• 2020 Annual Report
• 2019 Annual Report
• 2018 Annual Report
• 2017 Annual Report
• 2016 Annual Report
• 2015 Annual Report
• 2014 Annual Report
• 2013 Annual Report
• 2012 Annual Report

Publications

• Guh AY, Mu Y, Winston LG, et al. Trends in U.S. Burden of Clostridioides difficile Infection and Outcomes. N Engl J Med. 2020;382(14):1320-1330. doi:10.1056/NEJMoa1910215
• Skrobarcek KA, Mu Y, Ahern J, et al. Association between Socioeconomic Status and Incidence of Community-Associated Clostridioides difficile Infection - United States, 2014-2015. Clin Infect Dis. 2021;73(4):722-725. doi:10.1093/cid/ciab042
• Gargis AS, Karlsson M, Paulick AL, et al. Reference Susceptibility Testing and Genomic Surveillance of Clostridioides difficile, United States, 2012-17. Clin Infect Dis. 2023;76(5):890-896. doi:10.1093/cid/ciac817
• Guh AY, Fridkin S, Goodenough D, et al. Potential underreporting of treated patients using a Clostridioides difficile testing algorithm that screens with a nucleic acid amplification test. Infect Control Hosp Epidemiol. Published online January 25, 2024. doi:10.1017/ice.2023.262
• Guh AY, Li R, Korhonen L, et al. Characteristics of patients with initial Clostridioides difficile infection (CDI) that are associated with increased risk of multiple CDI recurrences. Open Forum Infectious Diseases. Published online March 6, 2024. doi:https://doi.org/10.1093/ofid/ofae127

About the data

Methods

EIP sites conducting surveillance

Case definitions

Incident case

When the following criteria is met for a patient who lives in the surveillance area:

• A patient with a positive C. difficile toxin assay or a positive C. difficile molecular assay (e.g., PCR) of a stool specimen who did not have a positive specimen in the prior 8 weeks.
  • Patient must be at least 1 year old.
  • For surveillance purposes, an individual may be classified and captured as a new incident case if 8 consecutive weeks have elapsed since their last C. difficile-positive test.

Recurrent episodes

• Patients with a positive C. difficile stool specimen between 2 and 8 weeks of the last positive specimen.

Duplicate episodes

• Patients with a positive C. difficile stool specimen less than 2 weeks since the last positive specimen.

Case ascertainment

EIP site staff identify cases based on reports of positive C. difficile toxin assay or C. difficile nucleic acid amplification assay from clinical, reference and commercial laboratories serving residents of the surveillance areas.

EIP site staff record information on additional positive specimens from the same patient to identify and track recurrent or duplicate episodes, as well as new cases.

Data collection

EIP site staff perform a brief medical-record review of all* incident CDI cases to collect the following data:

• Basic demographic characteristics.
• Location of stool collection.
• Healthcare exposures.

EIP site staff do not review records of recurrent or duplicate episodes.

*In Colorado and Georgia (the EIP sites with the largest surveillance populations), EIP site staff review a random sample of incident cases.

Epidemiologic classification categories

1. Healthcare facility-onset (HCFO) if the positive stool specimen collected is either:
   1. Greater than three calendar days after hospital admission.
   2. In a resident of a long-term care facility.
2. Community-onset healthcare facility-associated (CO-HCFA) if the positive stool specimen collected is:
   1. Either in an outpatient setting or within 3 calendar days after hospital admission.
   2. In a person with documented overnight stay in a healthcare facility (i.e., hospitalization or long-term care facility stay) in the 12 weeks before stool specimen collection.
3. Community–associated (CA) if positive stool specimen collected is:
   1. Either in an outpatient setting or within 3 calendar days after hospital admission.
   2. In a person with no documented overnight stay in a healthcare facility during the 12 weeks before the specimen collection.

A portion of cases subsequently undergo a comprehensive medical record review for clinical information and relevant risk factors.

Laboratory characterization

EIP site staff collect a convenience sample of stool specimens from incident CDI cases for whom case report forms have been completed. Stool specimens are sent to reference laboratories for culture. C. difficile isolates obtained from these cultures are sent to CDC for molecular typing and characterization.

Resources

Case report form for EIP surveillance staff

2024 CDI

More information

• Trends in U.S. Burden of Clostridioides difficile Infection and Outcomes
• Federal Register: Findings of Research Misconduct in Oregon (06/01/2015)