Wednesday, June 15, 2011

What causes C-diff infection?

Source: Serenity, Wikimedia

Clostridium difficile takes advantage of a void in the intestinal flora to grow and cause illness. Long-term antibiotic therapy and exposure to health care settings are risk factors for infection with this bacteria. However, exposure to the pathogen is by fecal contamination - meaning that proper hygiene and sanitation practices can minimize, and often eliminate, risk of infection.

Clostridium difficile is a bacterium that infects the gastrointestinal system, causing colitis, inflammation of the colon. Healthy adults are usually not susceptible to C. difficile infection, but the elderly and those in the hospital (particularly those undergoing prolonged antibiotic use) are more at risk of being infected. Hand washing and proper hygiene are basic preventive measures against C. diff, but the bacteria are becoming more common in hospital and nursing home settings. The bacterium is passed in the feces. Contact with contaminated material and then touching the face can infect another individual. Some spread is via health care workers and the close space of nursing homes. Some individuals carrying the bacteria do not get sick but can still spread the pathogen.

C. difficile often causes an infection after antibiotic use because the antibiotics kill off much of the natural flora in the intestines. Several strains of bacteria aid in food digestion and normal body functions, not causing infection as they cooperate with the human body. Wiping out these bacteria allows less symbiotic bacteria, like C. diff, to grow more readily. Once growing, the Clostridium bacteria produce toxins that destroy the lining of the intestines, resulting in patches of inflammation that cause the symptoms of infection. When the natural flora returns, the competition keeps the less beneficial bacteria in check.

Antibiotic resistant C. diff strains have appeared, including a clindamycin and erythromycin-resistant strain identified in 2000 that has already caused epidemic outbreaks in the United States and UK. This antibiotic resistant strain of C. diff produces more aggressive toxins, causing disease in healthy adults.

The symptoms of infection include diarrhea, which is defined as feces watery in consistency and occurring at least three times a day for two or more days; a loss of appetite; nausea; abdominal pain and tenderness; and fever. Severe and untreated infection, often indicated by blood in the watery stool, can progress to sepsis, a bacterial infection of the blood, which is often fatal.

C. diff is diagnosed by stool sample testing and treated by antibiotics, with a normal course lasting at least 10 days. Probiotics are sometimes used to increase the growth of good bacteria, and surgery to remove any heavily damaged portions of the intestine is an additional measure that may be taken by a health care provider. Before the treatment of C. diff infection, the original antibiotic treatment that triggered the infection is halted first. For resistant strains, different antibiotics may have to be attempted for treatment before one that works is found.

Preventing infection is easier than treating it, and previous infections increase the risk of future disease. C. diff infection is most readily prevented by good hygiene, which consists of washing hands with warm water and mild soap (not antibacterial soap) after using the restroom and before eating; properly sterilizing hospital instruments and surfaces; health care workers using disposable gloves and instruments; washing household surfaces in the kitchen and bathroom with disinfectants on a regular basis; and avoiding unnecessary antibiotic and antibacterial use.

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