Clostridioides difficile Infection

In C. difficile infection (CDI), the bacteria produce toxins that can cause inflammation of the colon (colitis) and diarrhea. It usually develops after antibiotics are taken to treat an infection. Many antibiotics alter the balance between the types and number of bacteria that live in the intestine. Thus, certain disease-causing bacteria, such as C. difficile, can overgrow and replace the harmless bacteria that normally live in the intestine. C. difficile is the most common cause of diarrhea that develops after antibiotics are taken. C. difficile infection is usually occurs when antibiotics are taken by mouth, but it also occurs when antibiotics are injected into a muscle or given by vein (intravenously).

When C. difficile bacteria overgrow, they release toxins that cause diarrhea, colitis, and sometimes formation of abnormal membranes (pseudomembranes) in the large intestine.

A deadlier strain of C. difficile is the cause of some hospital outbreaks. This strain produces substantially more toxin, causes more severe illness with greater chance of relapse, is easier to transmit, and does not respond as well to antibiotic treatment.

Almost any antibiotic can cause CDI, but clindamycin, penicillins (particularly ampicillin and amoxicillin), cephalosporins (such as ceftriaxone), and fluoroquinolones (such as levofloxacin and ciprofloxacin) have the highest risk of causing colitis. CDI can occur even after antibiotics have been taken for a very short time. Certain cancer chemotherapy medications may also lead to CDI.

Other risk factors for CDI include:

• Advanced age

• Having one or more other severe disorders

• Staying for an extended time in the hospital

• Living in a nursing home

• Abdominal surgery

• Having a disorder or taking a medication that decreases gastric acidity

Surgery involving the stomach, small intestine, or large intestine can upset the balance of bacteria in the digestive tract and increase the risk of developing CDI.

Medications that decrease gastric acidity include proton pump inhibitors and histamine-2 (H2) blockers, which are used to treat gastroesophageal reflux and peptic ulcer disease.

Sometimes the source of the bacteria is the person's own intestinal tract. For example, C. difficile is commonly present in the intestines of some healthy adults, hospitalized adults, and people who live in long-term care facilities (such as a nursing home). In these people, C. difficile bacteria typically do not cause symptoms or illness unless they overgrow. However, these people can spread clostridia to at-risk people. Person-to-person spread can be prevented by meticulous hand washing.

People may also get the bacteria from pets or the environment.

Symptoms typically begin 5 to 10 days after starting antibiotics but may occur on the first day or up to 2 months later.

Symptoms vary according to the degree of inflammation caused by the bacteria, ranging from slightly loose stools to bloody diarrhea, abdominal pain and cramping, and fever. Nausea and vomiting are rare.

People who develop a severe infection called fulminant colitis have more pain and are very ill. They may develop life-threatening dehydration, fast heart rate, low blood pressure, and perforation of the large intestine.

• Stool studies

• Sometimes sigmoidoscopy

Doctors suspect CDI in anyone who develops new and persistent diarrhea within 2 months of using an antibiotic or within 72 hours of being admitted to a hospital.

Doctors confirm the diagnosis by using stool tests. Doctors test for toxins produced by C. difficile as well as for a certain enzyme released by the bacteria. Doctors also do tests using the polymerase chain reaction (PCR) technique to detect the presence of the bacteria's genetic material (DNA) in the stool.

Doctors can also diagnose CDI by inspecting the lower part of the inflamed large intestine (the sigmoid colon), usually through a sigmoidoscope (a flexible viewing tube) or the entire colon with a colonoscope. If they see a specific type of inflammation called pseudomembranous colitis, CDI is the likely diagnosis.

Doctors may do imaging tests, such as abdominal x-rays or computed tomography (CT) scans, if they suspect a serious complication, such as perforation of the large intestine or fulminant colitis.

• Stopping use of the antibiotic causing the diarrhea

• Antibiotics effective against C. difficile

• For recurrences, antibiotics

• For frequent recurrences, sometimes a fecal (stool) transplant

People who develop diarrhea while taking an antibiotic that is likely to cause C. difficile–induced diarrhea should stop taking the antibiotic as soon as possible.

Most people who have C. difficile infection (CDI) are treated with the antibiotic vancomycin or fidaxomicin given by mouth for 10 days. infection (CDI) are treated with the antibiotic vancomycin or fidaxomicin given by mouth for 10 days.Fidaxomicin is more effective than vancomycin in decreasing the risk of symptoms returning.

Medications that people sometimes take to slow the movement of the intestine and treat diarrhea (such as loperamide) should not be taken. Such medications may prolong or worsen the diarrhea by keeping the disease-causing toxin in contact with the large intestine. Medications that people sometimes take to slow the movement of the intestine and treat diarrhea (such as loperamide) should not be taken. Such medications may prolong or worsen the diarrhea by keeping the disease-causing toxin in contact with the large intestine.

Occasionally, CDI is so severe that the person must be hospitalized to receive intravenous fluids, electrolytes (such as sodium, magnesium, calcium, and potassium), and, rarely, blood transfusions if bloody diarrhea has caused significant blood loss.

Rarely, surgery is required. For example, surgical removal of the large intestine (colectomy) may be needed in severe cases as a lifesaving measure.