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Clostridioides difficile Infection


Clostridioides difficile (formally Clostridium difficile) is a spore-forming anaerobic gram-positive bacterium. C. difficile infection (CDI) is a major cause of healthcare-associated diarrhoea, most often affecting elderly patients with other underlying diseases. C. difficile is spread via the faecal-oral route.

Clinical features

difficileinfection symptoms are similar to those of other diarrheal illnesses. After antibiotic therapy, diarrhoea usually starts in 5–10 days (from a few days to 2 months). It ranges from mild to severe, foul-smelling diarrhoea, which may contain blood/mucus. This can be associated with fever, leukocytosis, and abdominal pain. Faeces from patients with CDI have a characteristic smell like horse manure. The illness is mild in most patients, and full recovery is usual. Elderly patients may become seriously ill with dehydration. Complications include pancolitis, toxic megacolon, perforation, and endotoxin shock; occasionally, patients may develop pseudomembranous enterocolitis.

Risk factors for the development of CDI

  • Debilitated elderly (> 65 years) patients with comorbid conditions and poor host immune response. Any age group, except very young children (< 2 years), may be susceptible.
  • Prolonged stays in healthcare facilities, especially where difficile is endemic
  • Exposure to antibiotics, especially cephalosporins, quinolones, clindamycin, and co-amoxiclav
  • Exposure to difficle spores in a contaminated environment, items, equipment, and other symptomatic and asymptomatic individuals
  • Immunosuppressed patients, e.g., HIV, haematopoietic stem cell transplantation, patients with malignancy, and patients on immunosuppressive agents
  • Gastrointestinal disease, e.g. inflammatory bowel disease and gastrointestinal surgery
  • Exposure to gastric acid-suppressing medication, e.g., H2 antagonists and proton pump inhibitors
  • The presence of a nasogastric tube and patients on enteral feeding.


Stool specimens for testing of CDI should be sent to the microbiology laboratory for suspected patients with diarrhoea and/or abdominal pain with recent exposure to antibiotics and those with other risk factors.

The testing of C. difficile should be done if a patient has diarrhoea (a stool sample must take on the shape of the container) that is not attributable to an underlying condition, e.g. inflammatory colitis, overflow, or therapy (e.g. laxatives, drugs, or enteral feeding). C. difficile can be present in up to 5 % of healthy individuals without symptoms. Hence, screening of stool samples of asymptomatic patients is not necessary.

All diarrhoeal samples from hospital in-patients aged >2 years where clinically indicated should be tested for CDI. The Bristol stool chart classifies human faeces into seven categories based on stool samples’ relative density, which should be used as a guide for testing CDI.

The stool sample is first screened by testing for glutamate dehydrogenase (GDH) or by polymerase chain reaction (PCR). If positive, the presence of toxins must be confirmed using a toxin test. The sample should be transported as soon as possible and stored at 2–8°C until tested due to toxin inactivation.

Once the diagnosis has been confirmed, repeat specimens for clearance should not be taken unless there is a relapse following treatment. It is not uncommon for the faeces to remain toxin-positive after treatment, even when the patient’s symptoms have settled. Persistently positive test results at the end of treatment are not predictive of a C. difficile relapse.

Management of C difficile Cases

Early identification through triage is essential. Early diagnosis, prompt isolation, and starting treatment as soon as possible to control symptoms are essential factors in preventing the spread of CDI. In addition, known patients with CDI may remain colonized for a long time after discharge. Therefore, once positive, the patient’s notes should be flagged on electronic records to identify them immediately upon re-admission.

Sporadic case
  • It is essential to isolate the patient within 2 hours in a single room with en suite toilet and shower facilities. If an ensuite single room is not available, provide a dedicated commode in the same room. If the patient is on antibiotic treatment, review and stop antibiotic(s) unless essential or change antibiotic(s) to a narrow spectrum to one with a lower risk of causing difficile infection.
  • Start difficile treatment as soon as possible – refer to hospital guidelines. C. difficile treatment is considered a “critical medicine” in some trusts, meaning that timeliness of administration is crucial. Contact microbiology if advice is required.
  • Perform hand hygiene using soap and water.
  • Provide the patient with a ‘Patient Information Leaflet.’
  • All reusable items and equipment must be decontaminated after use.
  • Environmental cleaning and disinfection are essential using detergent and chlorine-based disinfectants or approved sporicidal products. Ensure deep cleaning and disinfection of rooms after discharge of CDI patient.
  • Unnecessary movement and transfer of patients between wards/units and healthcare should be restricted.
  • A Bristol stool chart should be started and updated following every bowel action and completed daily, even if there are no bowel movements. This is in addition to daily clinical assessment of CDI patients.
  • All linen should be managed as infected linen, and all waste should be disposed of as clinical waste.
  • In a hospital setting, all cases of CDI are reported to the Infection Prevention and Control Team.
  • In the community, consider seeking prompt specialist advice from a microbiologist or infectious diseases specialist. Refer people in the community with suspected or confirmed difficile infection to the hospital if they are severely unwell or their symptoms or signs worsen rapidly or significantly at any time.
Localized Cluster

In addition to the above (sporadic case), the following actions should be implemented:

  • There should be a case review by the clinical and Infection Prevention & Control Team.
  • Senior managers should be informed as soon as possible and be updated daily.
  • Staff deployment to and from other areas must be controlled to ensure adequate staffing levels whilst minimizing the risk of difficile transmission.
  • Inform the laboratory so that stool specimens are sent for ribotyping.
  • Implement enhanced environmental cleaning in the affected areas and increase the frequency to at least twice daily.
  • Managers are responsible for ensuring staff are aware of the difficile policy and comply with all aspects. They are also responsible for ensuring adequate staffing levels are available to implement IPC practices effectively, and resources are available for increased cleaning frequency and ensure sufficient supplies of items and equipment.
  • In addition to the above (‘Sporadic case’ and a ‘Localized cluster’), the following action should be implemented.
  • In a hospital situation, an Outbreak Control Team should be convened as per the local Outbreak plan.
  • Outbreaks should be reported to the Public Health Agency (Duty Room: tel no. 0300 555 0119)
  • Outbreaks of CDI may need to be reported as ‘Serious Adverse Incidents’.
  • The ward/area/facility should be closed to new admissions, and unnecessary transfers should be avoided.

Note: Large outbreaks of C. difficile with significant mortality have been documented in healthcare facilities and often resulted in public enquiries.

Robust management to prevent secondary spread is essential.

Key references and further reading