What is Clostridioides difficile infection (CDI)?

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From the Guidelines

Clostridioides difficile infection (CDI) is a bacterial infection that primarily affects the colon, causing symptoms ranging from mild diarrhea to severe, life-threatening inflammation of the colon (colitis). It occurs when C. difficile bacteria, which are naturally resistant to many antibiotics, multiply in the intestines after the normal gut microbiota has been disrupted, typically by antibiotic use 1. The bacteria produce toxins that damage the intestinal lining, leading to characteristic symptoms including watery diarrhea (often with mucus or blood), abdominal pain, fever, and elevated white blood cell count. CDI is particularly common in healthcare settings and among elderly patients who have recently taken antibiotics. Some of the key risk factors for CDI include:

  • Advanced age
  • Exposure to antibiotic agents, particularly third-/fourth-generation cephalosporins, fluoroquinolones, carbapenems, and clindamycin 1
  • Duration of hospitalization
  • Gastrointestinal surgery or manipulation of the gastrointestinal tract
  • Cancer chemotherapy
  • Immunocompromised state, such as in patients with human immunodeficiency virus infection Treatment typically involves discontinuing the inciting antibiotic when possible and administering specific antibiotics effective against C. difficile, such as oral vancomycin (125 mg four times daily for 10 days), fidaxomicin (200 mg twice daily for 10 days), or metronidazole (500 mg three times daily for 10 days) for milder cases 1. Severe or recurrent infections may require longer treatment courses, combination therapy, or fecal microbiota transplantation to restore healthy gut bacteria. Prevention focuses on proper antibiotic stewardship, thorough hand hygiene, and environmental cleaning, as C. difficile spores can persist on surfaces for months 1. It is essential to note that the risk of CDI recurrence increases with each successive recurrence, and the attributable mortality of CDI can be significant, ranging from 4.5% to 16.7% in different studies 1. Therefore, prompt and accurate diagnosis, effective treatment, and prevention strategies are crucial to reduce the morbidity, mortality, and impact on quality of life associated with CDI.

From the Research

Definition of CDI

  • CDI stands for Clostridioides difficile infection, a range of debilitating intestinal symptoms caused by the bacterium Clostridioides difficile 2.
  • It is a major cause of diarrhoea for inpatients as well as outpatients, usually associated with changes in the normal intestinal microbiota caused by administration of antibiotics 3.

Risk Factors and Symptoms

  • Risk factors for CDI include recent exposure to health care facilities or antibiotics, especially clindamycin 4.
  • CDI is characterized by a wide range of symptoms, from mild or moderate diarrhea to severe disease with pseudomembranous colitis, colonic ileus, toxic megacolon, sepsis, or death 4.
  • Elderly and immunocompromised patients are at greater risk for CDI and CDI recurrence 3.

Treatment Options

  • The cornerstones for the treatment of CDI are vancomycin and fidaxomicin 3.
  • Metronidazole should be used only in mild-to-moderate disease in younger patients who have no or only few risk factors for recurrence 3.
  • Fecal microbiota transplantation (FMT) is a reasonable treatment option with high cure rates in patients who have had multiple recurrent episodes and have received appropriate antibiotic therapy for at least three of the episodes 4, 5.
  • Bezlotoxumab infusion, a monoclonal antibody against C. difficile toxin B, may be considered as an adjunctive therapeutic strategy in addition to the standard care provided to patients with several risk factors for recurrence 3, 5.

Prevention and Management

  • Good antibiotic stewardship is a key strategy to decrease rates of CDI 4.
  • Hands should be cleaned with either soap and water or an alcohol-based product, but during outbreaks soap and water is superior 4.
  • The Infectious Diseases Society of America does not recommend the use of probiotics for prevention of CDI 4.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Clostridioides difficile Infection: Update on Management.

American family physician, 2020

Research

Update of treatment algorithms for Clostridium difficile infection.

Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases, 2018

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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