The characteristics, diagnosis, management, surveillance and epidemiology of Clostridium difficile (C. difficile).Clostridium difficile (C. difficile) is a bacterium that’s found in people’s intestines. It can be found in healthy people, where it causes no symptoms (up to 3% of adults and 66% of babies).

C. difficile causes disease when the normal bacteria in the gut are disadvantaged, usually by someone taking antibiotics. This allows C. difficile to grow to unusually high levels. It also allows the toxin that some strains of C. difficile produce to reach levels where it attacks the intestines and causes mild to severe diarrhoea.

C. difficile can lead to more serious infections of the intestines with severe inflammation of the bowel (pseudomembranous colitis). C. difficile is the biggest cause of infectious diarrhoea in hospitalised patients.

You can become infected with C. difficile if you ingest the bacterium (through contact with a contaminated environment or person). People who become infected with C. difficile are usually those who’ve taken antibiotics, particularly the elderly and people whose immune systems are compromised.

General CharacteristicsClostridium difficile is a species of Gram-positive, rod-shaped, spore-forming bacteria. C. difficile are anaerobic—lives in the absence of oxygen. In the presence of oxygen, the vegetative form of C. difficile can survive up to 24 hours on an inanimate surface; whereas, C. difficile spores can survive up to 2 years on inanimate surfaces that are exposed to oxygen.

-Habitat: C. difficile inhabits the microflora of intestines of humans. The number of C. difficile bacteria is kept very low and in control by the millions of harmless bacteria in the intestines that aid in digestion. C. difficile reproduces by binary fission.

-Nutrition : C. difficile is heterotrophic which means that it cannot make its own food and relies on organic substances for nutrition.

The pathology C.difficile enter the body Via ingestion of spores through fecal-oral route, often through touching contaminated surfaces.

In an otherwise healthy person, the person’s normal microflora of the intestines prevents C. difficile from growing due to limited space and resources. However, when people are taking significant amounts of antibiotics to treat another illness, the antibiotics kill off the normal microflora of the intestines allowing C. difficile to colonize the intestine and grow out of control. C. difficile is most often acquired nosocomially (acquired secondary to a primary hospitalization) because, in the hospital, patients are often on broad-spectrum antibiotic therapy (antibiotics, such as clindamycin, used to treat a number of bacterial infections) to

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Clostridium difficl

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prevent any infection. Nevertheless, these antibiotics can cause pathogenic strains of C. difficile to grow out of control.

How does Clostridium difficile cause disease?

If the normal microflora of a person infected with C. difficile has Intestine with Pseudomembranous colitis (From: Johnson, M. T. 2009)

Been disrupted by antibiotic therapy, C. difficile bacteria are able to reproduce in the intestinal crypts. Pathogenic strains of C. difficile causes disease by the release of two protein enterotoxins, toxin A and toxin B, which cause severe inflammation and mucosal injury to the colon--colitis. At this point, the toxins attract white blood cells to the area, and the white blood cells may provide a protective immune response. However, if the white blood cells do not provide the desired immune response, mild CDAD occurs. Nevertheless, the toxins can actually kill the lining of the intestine, causing it to fall off and mix with the white blood cells and give the appearance of yellow plaques (patches) in the intestines. This is called pseudomembranous colitis because the patches look like membranes but aren’t true membranes.

The symptoms Mild CDAD

* Non-bloody, watery diarrhea (5-10 watery stools a day)

* Low-grade fever

*Abdominal cramping

*Dehydration

*Nausea

*Loss of appetite

Pseudomembranous colitis (in addition to mild symptoms)

*Profuse watery diarrhea (greater than 10 watery stools a day)

*High fever (102°F—104°F)

*Blood in the stool

*Weight loss

*Severe abdominal pain and tenderness

*Death (6%-30% mortality rate)

. diagnosis and treatment One of the most common C. difficile tests is a two-step rapid immunochromatography

method. The first step detects the presence of C. difficile bacteria. Since not all C. difficile bacteria are toxigenic, the second step involves detecting toxigenic strains of C. difficile. This is a rapid test with a turnaround time of less than one day and offers high sensitivity and specificity.

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Other tests include enzyme immunoassays (EIA) and tissue cytotoxic assays. A colonoscopy can also be performed to confirm pseudomembranous colitis.

Usually, the first step in treatment a C. difficile infection is to stop the antibiotic that helped to cause the infection. Oral metronidazole is used to treat mild CDAD, and vancomycin is used to treat severe CDAD. Usually plenty fluids (oral or intravenous) are given to the patient to help re-hydrate the patient from the fluids lost from the diarrhea.

Symptoms usually ease within 2-3 days after stopping the first antibiotic and beginning a metronidazole or vancomycin regimen. In patients with severe cases of pseudomembranous colitis, surgery may be performed to remove the infected portion of the colon.

Who is most likely to get a Clostridium difficile infection?

People who:*are taking more than one kind of antibiotic* have prolonged hospitalizations*are elderly*already have a disease of the intestines*are undergoing chemotherapy*have other serious diseases

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