Clostridium difficile


by Maricella Estrada

Disease Etiology:

Clostridium difficile [klo-STRID-ee-um dif-uh-SEEL] is a bacterium that causes diarrhea and other serious intestinal conditions such as colitis and pseudomembranous colitis. It's an overgrowth of C.difficile in the colon. Normal intestinal flora is killed off with antibiotics. When this happens the bacteria produces two toxins (A and B) damaging the cells that line the intestine walls. Clostridium difficile is recognized as a nosocomial pathogen. [1],[11]


Means of Transmission:

C.difficile is spread from person to person by the fecal oral route. Contaminated areas like keypads, equipment, toilet areas, bed pan washers, and light switches also pass along the bacteria.[8] People who fail to sanitize hands will transfer the bacteria to patients and tend to contaminate everyday use items.



Clostrodium difficile naturally resides in the intestines of human beings.  This bacterium can grow spores and remain quite a while in the intestines where there is no oxygen.[1],[9] Mainly found in infants where its toxins do not damage their intestinal cells. There is less than 5% found in adults.


Specific Characteristics:

C.difficile is classified as a spore-forming anaerobic rods (bacillus), gram-positive, two types of toxins: Toxin A, enterotoxin, and Toxin B, cytotoxin.[12]


Specific Tests for Identification:

The method in detecting C.difficile toxin A, an enterotoxin and B, a cytotoxin is by a rapid enzyme immunoassay (EIA). It takes 1-4 hrs for the results to become available.  This type of test is only ordered when a patient has been taking a broad spectrum of antibiotics.[10] There is also another test that can detect toxins A and B: enzyme-linked immunosorbent assay (ELISA).  C. difficile can also be cultured from faeces anaerobically.  Packaged correctly and sent to the laboratory for typing and testing for susceptibility to antibiotics. [1]


Historical Information:

In 1893, Pseudomembranous colitis (PMC) was first accounted for  when a 22 yr. old female who had gastric polyp resection.  C.difficile is a toxin that is found in PMC. C.difficile was named by investigators who found it difficult to culture.[10]  “Clostridium difficile was first described in 1935, but it's association with the disease was not identified until 1978.“ It's now recognized as an important nosocomial pathogen that may connected  with morbidity and mortality rates.[11]


Signs and Symptoms of disease:

Some people come in contact with C.difficile and are asymptomatic and others acquire C.difficile associated diarrhea.[11] This follows with watery diarrhea with foul odor (at least 3 bowel movements/day for 2 or more days), fever, loss of appetite, nausea, and abdominal pain or tenderness. [1], [10] In adults, the best signs are significant diarrhea, recent exposure to antibiotics and colitis. The majority would be adults over the age of 65, severely ill people who undergo antibiotic therapy, who reside in long-term care facilities, and medically hospitalized patients. [1]


Microbial Virulence Factors:

Clostridium difficile-associated diarrhea (CDAD) occurs more frequently with clindamycin compared to other agents such as broad spectrum cephalosporins and penicillin, but any topical antibiotic (table 1 below) can lead to the disease.[5],[9],[10] Antibiotics cause the normal flora in the intestines to breakdown. This activates sporulation which can lead to overgrowth of the endospores. The bacteria C.difficile releases toxins (A and B) that cause severe abdominal pain.[9],[10] This gastrointestinal infection ranges from asymptomatic to severe diarrhea, pseudomembranous colitis, toxic megcolon to intestinal perforation and possibly death. [1],[9] “C.difficile toxins can be found in the stool of 15-25% of patients with antibiotic associated diarrhea and more than 95% of patients with pseudomembranous colitis.“ [8] The virulence of the organism has more than doubled in the past 5 years.[6]                 


Control/Treatment for disease:

The preferred method of hygiene to control the spread of C.difficile is hand washing. Wash hands with soap and water every time you remove gloves after caring for patients with diarrhea. Alcohol based hand-rubs are not effective against the spores of C.difficile. It's better to use them after hand-washing. [1] Proper removal of gloves is of extreme importance when working with patients that have diarrhea. Only use antibiotics for serious  infections; prolong use may result in bacteria becoming resistant. [4] The drug therapy for C.difficile infections are oral metronidazole and vancomycin.  Vancomycin is usually used for more severe cases. [10]


Prevention of disease:

With any infectious disease, wash hands with warm soapy water every chance you get for at least 20 seconds if not for 2 minutes. Working in a  health care facility wether its a long/short-term or a hospital hand washing is critical before/after you see a patient. Talk to your doctor about any concerns you have with taking antibiotics.[1] To prevent the spread of C.difficile, facilities isolate the patients with the disease to a single room with a bathroom. [8] Two main actions on how prevent the disease are:

                   1. to interrupt the spread of disease by utilizing infection control.

                   2. reduce the risk of the patient acquiring the disease. 


Current cases/outbreaks locally:

Clostridium difficile has increased tremendously over the years.“...diagnosis doubled from 82,000 in 1996 to 178,000 in 2003.“... The overall rate during this period was severalfold higher in persons >65 years of age (228/100,000) than in the age group with the next highest rate, 45–64 years (40/100,000; p<0.001). CDAD appears to be increasing rapidly in the United States and is disproportionately affecting older persons.“[13] These increasing numbers are associated with improper sanitization of the room or medical instruments, i.e. electronic thermometers.


Current cases/outbreaks globally:

In Europe the C. difficile infection has increased in recent years, similar to the in the U.S.  “a 2-month surveillance study in 38 hospitals from 14 European countries. Of 322 toxinogenic isolates, only 20 (6.2%) were typed as NAP1/BI/027 and most cases were reported from Ireland, Belgium and The Netherlands. A more recent surveillance study showed that the NAP1/BI/027 strain now accounts for 30% of all CDI isolates obtained in Denmark, 49% of all CDIs in Finland, and 42% of all in England.”[14] They began giving an antibiotic and the infected people showed up in the hospitals no more than 6 months after treatment. Health care workers who were in contact with infacts who tested positive for the C.difficile strain.



[1]It's Your Health. “C.difficile” (Clostridium difficile) June 2006.     2/18/2009


[2]A simple guide to Clostridium difficile. Dept of Health. Last modified date: 8 February 2007     2/21/2009


[4] Clean Care is Safer Care “System change-changing hand hygiene behavior at the point of care” Last update unknown   2/21/2009

[5] Texas Department of State Health Services “Microbiology Lab Tests” Last update uknown.     2/21/2009


[6] Allison Imhoff, PharmD and Kelly Karpa, Phd, RPh“Is There a Future for Probiotics in Preventing Clostridium difficile-Associated Disease and Treatment of Recurrent Episodes?” Nutrition in Clinical Practice, Vol,24, No.1,15-32 (2009)     2/20/2009

[7] Jyotsna Jagai and Elena Naumova “Clostridium difficile-associated Disease in the Elderly, United States” CDC Emerging Infectious Diseases Vol. 15 No. 2 February 2009     2/20/2009


[8] Rebecca H. Sunenshine, Md and L.Clifford McDonald, MD “Clostridium difficile-associated disease: New challenges from an established pathogen Cleveland Clinic Journal of Medicine Vol. 73 No.2 Feb2006 2/20/2009


[9]Lab Tests Online “Clostridium difficile toxin” Last reviewed on Dec. 8/2007     2/20/2009

[10]Calin S. Moucha, MD, and Lisa L. Dever, MD “Clostridium difficile:  An old bug with a new twist” AAOS. 2/21/2009


[11] Susan M. Poutanen, Andrew E.Simor “Clostridium diffficile-associated diarrhea in adults“ 171 (1): 51.(2004), 2/19/2009


[12] “Clostridium difficile.“ last updated on 2/22/09 2/19/2009


[13] “Clostridium difficile Infection in Patients Discharged from US Short-stay Hospitals,“ 1996–20031L. Clifford McDonald, Maria Owings,* and Daniel B. Jernigan* Vol. 12 No.3 March 2006 *Centers for Disease Control and Prevention, Atlanta, Georgia, USA   2/20/2009


[14] Luke F. Chen, MBBS, FRACP; Daniel J. Sexton, MD CDI : A Global Perspective of an Epidemic. Posted 09/30/2008 2/21/2009