Clostridioides difficile (C. diff) is a bacterium that can lead to infections within the digestive system. It is capable of causing significant inflammation of the colon, a condition known as colitis, which results in severe diarrhea. While the bacterium can be present in the gut without causing issues, under certain conditions it can proliferate and release toxins that damage the intestinal lining.
How C. diff Infections Occur
The most common trigger for a C. diff infection is the disruption of the normal balance of bacteria in the gut, often referred to as the gut microbiota. This disruption frequently occurs following a course of broad-spectrum antibiotics. These medications can also eliminate beneficial bacteria in the intestine that would normally keep C. diff populations in check. When these competing bacteria are removed, C. diff can multiply rapidly and begin to produce toxins.
Several factors increase the risk of developing a C. diff infection, including:
- Being over the age of 65.
- A recent stay in a hospital or long-term care facility, where the bacteria are more common.
- A weakened immune system, due to a chronic condition like kidney failure or treatments such as chemotherapy.
- Having a previous C. diff infection.
The bacterium is transmitted through spores, which are a hardy, dormant form of the bacteria shed in feces. These spores can survive for long periods on surfaces, hands, and food, and are resistant to many common cleaning agents. Infection occurs when these spores are ingested, often through contact with a contaminated environment.
Recognizing the Symptoms
The defining symptom of a C. diff infection is watery diarrhea, which occurs multiple times throughout the day. In mild cases, an individual might experience at least three bowel movements a day. This is often accompanied by abdominal cramping and tenderness. Some people may also experience a loss of appetite and nausea.
As an infection becomes more severe, the frequency of diarrhea can increase to as many as 10 to 15 times a day. Additional signs of a more serious condition include a fever and a rapid heart rate. In these advanced cases, it is also possible to see blood or pus in the stool, which indicates significant damage to the colon lining. Dehydration can become a concern due to the persistent fluid loss.
Diagnosis and Standard Treatments
When a C. diff infection is suspected, diagnosis is made through laboratory analysis of a stool sample. This testing is designed to detect the presence of the toxins produced by the C. diff bacteria or the bacterial genes responsible for producing them. Identifying these markers confirms an active C. diff infection.
Once a diagnosis is confirmed, the first step in treatment often involves discontinuing the antibiotic that triggered the infection, if medically feasible. A healthcare provider will then prescribe a different antibiotic specifically targeted to eliminate C. diff. The standard first-line medications for an initial infection are oral vancomycin or fidaxomicin. These drugs are effective at killing the multiplying C. diff bacteria in the colon.
A typical course of these targeted antibiotics lasts for 10 days. While metronidazole was previously used, it is no longer recommended as a primary treatment for initial infections but may be used if other options are unavailable. Most infections respond well, with symptoms improving within a few days of starting the medication, though a full recovery can take one to two weeks.
Managing Recurrent and Severe Infections
A challenge with C. diff is its tendency to recur, with about 1 in 5 people experiencing a return of symptoms after treatment. A recurrent infection is another episode that occurs within a few weeks of completing therapy. This happens because the initial antibiotic treatment kills the active bacteria but does not eliminate the dormant spores, which can later germinate and cause the infection to return.
For patients who experience multiple recurrences or have a severe infection that does not respond to standard antibiotics, more advanced treatments are required. One of the most effective interventions is fecal microbiota transplantation (FMT). This procedure involves transferring stool from a healthy donor into the patient’s colon to reintroduce a diverse population of beneficial gut bacteria, restoring a healthy balance and preventing C. diff from overgrowing.
Another advanced option for preventing recurrences is the use of monoclonal antibodies like bezlotoxumab. This antibody is designed to target and neutralize one of the main toxins produced by C. diff. By neutralizing the toxin, bezlotoxumab helps prevent the colon damage that causes symptoms, reducing the likelihood of another relapse. For severe, life-threatening cases known as fulminant colitis, a combination of high-dose oral vancomycin and intravenous metronidazole may be administered.
Prevention in Healthcare and at Home
Preventing the spread of C. diff involves targeted hygiene practices and careful antibiotic use. Because C. diff spores are resistant to alcohol, handwashing with soap and water is more effective than using alcohol-based hand sanitizers. Thorough handwashing physically removes the spores from the skin and is important after using the restroom and before eating.
In environments where an infection is present, cleaning surfaces with a disinfectant containing bleach is necessary to kill the hardy spores. At home, this means focusing on cleaning bathrooms and frequently touched surfaces with appropriate products if a household member is infected.
A broader strategy for prevention is antibiotic stewardship, which involves the responsible use of antibiotics. This means only taking these medications when necessary and using a narrow-spectrum antibiotic if possible. Narrow-spectrum drugs target a more specific range of bacteria, reducing the collateral damage to the gut’s beneficial microbial community and lowering the risk of a C. diff infection.