Clostridioides difficile (C. diff) is a spore-forming bacterium that causes severe diarrheal illness and inflammation of the colon (colitis). This organism produces potent toxins that damage the lining of the large intestine. While it can affect anyone, the infection is often associated with healthcare facilities like hospitals and nursing homes. C. diff infections lead to nearly half a million infections in the United States annually.
Risk Factors and How the Infection Spreads
The primary cause that allows C. diff to establish an infection is the disruption of the gut microbiome, the complex community of healthy bacteria living in the intestine. Broad-spectrum antibiotics, which are designed to kill a wide range of bacteria, inadvertently destroy the beneficial gut flora that normally keep C. diff in check. Once this protective barrier is compromised, the opportunistic C. diff can rapidly multiply and begin producing its damaging toxins.
People are more likely to contract the infection while taking antibiotics or in the months immediately following treatment. Susceptibility also increases with advanced age, particularly for those over 65, and having underlying medical conditions or a weakened immune system. Prolonged stays in healthcare settings, where antibiotic use is frequent and the bacteria are prevalent, also elevate risk.
Transmission occurs through the fecal-oral route, involving the ingestion of highly resilient C. diff spores. These spores are the dormant form of the bacterium, possessing a protective coating that allows them to survive on environmental surfaces for months. Contaminated surfaces in hospitals, such as bed rails, medical equipment, and toilets, serve as reservoirs. Healthcare workers can unknowingly carry the spores on their hands or clothing, facilitating spread between patients.
Recognizing the Symptoms and Complications
Symptoms typically appear while a person is on antibiotics or shortly after the course is completed. Mild-to-moderate infection generally causes watery diarrhea occurring three or more times a day, accompanied by abdominal pain or tenderness and sometimes a low-grade fever. Patients may also experience loss of appetite and nausea.
A more severe infection can lead to profuse watery diarrhea, risking rapid dehydration. Severe dehydration can cause a drop in blood pressure and lead to kidney failure. Indicators of a worsening condition include the presence of blood or pus in the stool, a fast heart rate, and an increased white blood cell count.
The most severe complications are toxic megacolon and pseudomembranous colitis, both requiring immediate medical intervention. Pseudomembranous colitis involves severe inflammation of the colon and the formation of plaque-like patches of tissue called pseudomembranes. Toxic megacolon is a rare condition where the colon becomes acutely distended and unable to expel gas and stool. This can potentially lead to a perforation of the bowel wall and the development of sepsis.
Current Treatment Approaches
The initial step in treating a confirmed C. diff infection is to stop the antibiotic that triggered the imbalance, allowing the gut flora a chance to recover. The infection requires specific antibiotics that target C. diff without causing widespread damage to the remaining healthy gut bacteria. Oral vancomycin and fidaxomicin are the primary medications used, as they reach high concentrations in the colon where the infection resides.
Fidaxomicin is often favored because it is a narrow-spectrum antibiotic, disturbing the rest of the gut microbiome less than vancomycin. Metronidazole may be used for an initial episode of non-severe infection, but it is less effective for severe cases or preventing recurrence. The goal of this therapy is to stop the C. diff bacteria from growing and producing the toxins that cause inflammatory damage.
For patients who experience multiple infections, defined as two or more recurrences, Fecal Microbiota Transplantation (FMT) is a highly effective treatment option. This procedure involves introducing stool from a carefully screened, healthy donor into the patient’s colon, typically via colonoscopy or a capsule. The rationale is to immediately repopulate the patient’s gut with a diverse and healthy community of microorganisms. This infusion of healthy flora quickly outcompetes the pathogenic C. diff and restores the natural balance, with success rates often exceeding 90%.
Preventing Recurrence and Transmission
Preventing the spread of C. diff relies heavily on meticulous hygiene and environmental control due to the robust nature of the spores. Hand hygiene is particularly important, requiring the use of soap and water rather than alcohol-based hand sanitizers, which do not effectively kill the spores. This practice is essential for healthcare workers and visitors to an infected person.
Environmental cleaning protocols are modified to target the resistant spores using sporicidal agents, such as a diluted chlorine bleach solution, on frequently touched surfaces. This is necessary because standard cleaning products are often ineffective against the spore form of the bacteria. Patients with active infection are typically placed on contact precautions in healthcare settings to limit environmental contamination.
Recurrence is a significant challenge, with a high risk of the infection returning within two to eight weeks after initial treatment. The most important strategy for minimizing this risk is to avoid unnecessary use of antibiotics in the future. Patients should inform their healthcare providers about their C. diff history so that future antibiotic prescriptions can be carefully considered, opting for narrow-spectrum agents when possible.