CDAD

Clostridioides difficile-associated diarrhea (CDAD), also known as C. difficile infection (CDI), is a type of bacterial infection that affects the colon, leading to symptoms ranging from mild diarrhea to severe life-threatening inflammation of the colon (colitis). It is caused by the bacterium Clostridioides difficile (formerly known as Clostridium difficile), which can overgrow in the colon following the use of antibiotic medications that disrupt the normal balance of bacteria in the gut.

Causes and Risk Factors

CDAD occurs when Clostridioides difficile bacteria, which may be present in a dormant state in the environment or in the intestines of some individuals without causing harm, become active and proliferate. This overgrowth is often triggered by the use of antibiotics, which can kill beneficial bacteria in the gut, allowing C. difficile to thrive. Other risk factors include prolonged hospital stays, a weakened immune system, previous infections with C. difficile, and advanced age.

Symptoms

Symptoms of CDAD can range from mild to severe and include:

• Watery diarrhea (at least three bowel movements per day for two or more days)
• Fever
• Loss of appetite
• Nausea
• Abdominal pain or tenderness

In severe cases, CDAD can lead to more serious conditions such as pseudomembranous colitis, toxic megacolon, perforations of the colon, and sepsis.

Diagnosis

Diagnosis of CDAD involves a review of the patient's medical history, especially recent antibiotic use, and laboratory tests. The most common tests for detecting C. difficile infection include stool tests for the bacteria's toxins and PCR (polymerase chain reaction) tests for the bacteria's DNA.

Treatment

Treatment for CDAD typically involves stopping the use of the antibiotic that triggered the infection, if possible, and starting a course of antibiotics specifically targeted at C. difficile. The most commonly used antibiotics for treating CDAD are metronidazole, vancomycin, and fidaxomicin. In recurrent or severe cases, fecal microbiota transplantation (FMT) may be considered to restore a healthy balance of bacteria in the gut.

Prevention

Preventive measures for CDAD include judicious use of antibiotics, strict adherence to infection control practices in healthcare settings, and thorough handwashing with soap and water, as alcohol-based hand sanitizers may not be effective against C. difficile spores.

Complications

Complications of CDAD can be severe and include dehydration, kidney failure, bowel perforation, and death, particularly in vulnerable populations such as the elderly or those with weakened immune systems.