Infection Control: Stopping the Spread of Clostridium Difficile

Calvin Ice, ONU,PharmD Candidate, ICP Clinical Pharmacy Student

Clostridium difficile-associated diarrhea (CDAD) is the most common cause of infectious healthcare-associated diarrhea in patients, infecting up to 20% of inpatients (including symptomatic and asymptomatic patients).1,2 Its transmission is of great concern in the nursing home setting, as this patient population commonly possesses predisposing risk factors. The infection itself is caused by a gram-positive, spore-forming anaerobic bacillus that causes a toxin-mediated disease.1,2 C. diffi cile is commonly found in the environment, and it can exist for months on surfaces in spore form.3 The bacterium is transmitted by ingestion of the spores via the oral-fecal route.4

Over the last decade, the incidence of this infection has been increasing in the United States, and the elderly population remains the most likely group to acquire CDAD.3 From 2000 to 2005 it is estimated that the number of diagnoses on hospital discharge increased from 139,000 to 301,200.4 In addition to the increasing frequency of CDAD, the severity of the disease has worsened as well. During just a seven year span the number of deaths due to CDAD increased from 793 in 1999 to 6225 in 2006.4 In 2006, this sharp increase led to CDAD being ranked among the top 20 causes of death in adults ages 65 and older.3


Risk Factors:

Risk factors for acquiring CDAD are particularly common among the elderly, which leads to a high incidence of transmission in the nursing home setting.1,3 These include:
  • Age ≥ 60
  • Immunocompromised state
  • Exposure to antimicrobial agents
  • Recent hospitalization
  • Enteral tube feeding
  • Use of gastric acid suppressants (ex. omeprazole).
Antibiotic use, including duration and agent, is the most signifi cant modifi able risk factor in CDAD, as disruption of the normal colonic fl ora allows for colonization by the C. diffi cile bacterium. Additionally, the rate of recurrent CDAD episodes is higher among those ≥ 65 years of age.4

Infection Control Measures:

Due to the spore formation of C. diffi cile, CDAD can spread rapidly among patients, particularly in the nursing home setting where other patients present with impaired health status and other CDAD risk factors, such as age &ge 60 and widespread use of gastric acid suppressants. To help reduce the likelihood of infection transmission, the following steps toward infection control should be taken:

Step 1: Isolation

An important measure in controlling spread of C. diffi cile is proper isolation of infected patients. Studies have demonstrated that patients are more likely to acquire CDAD when housed in double rooms versus housing in single rooms. Additionally, evidence also supports the use of contact precautions such as gowns and vinyl gloves for healthcare personnel. These precautions have demonstrated an ability to prevent the spread of bacteria from patients who present with diarrhea, as these patients are most likely to cause the nosocomial spread of CDAD.

Step 2: Hand Hygiene

Another important step in controlling the horizontal transmission of C. diffi cile is the use of proper hand hygiene. Studies have shown that use of an alcohol-based sanitizing gel only displaces bacterial spores and does not kill them. Hand washing with antibacterial soap and running water proved more effective in mechanically displacing and killing the bacteria and spores to reduce infection spread. It has been demonstrated that healthcare personnel use of vinyl gloves, along with this proper hand hygiene, results in decreased spread of CDAD.

Step 3: Decontamination of Equipment

The transmission of C. difficile has also been found to occur through the contamination of toilets, blood pressure cuffs, thermometers, and other items that are used by multiple patients. Studies demonstrate that the use of 1,000 parts per million (ppm) chlorine cleaner reduces the environmental spread of the bacteria and its spores. As such, all CDAD patient rooms and interchangeable items should be thoroughly disinfected with this cleaner prior to utilization by new patients. Additionally, it has been recommended that the use of disposable thermometers can help to further decrease the risk of nosocomial infection spread.

Summary:

To effectively reduce the transmission of C. diffi cile the Infectious Disease Society of America (IDSA) recommends combining the three steps of infection control to achieve a more favorable result than any single step could achieve on its own.3 In summary, the following precautions should be promoted to decrease the spread of CDAD in healthcare facilities:
  • Isolate infected patients and use contact precautions
  • Wash hands with antibacterial soap and running water (alcohol will not kill spores)
  • Disinfect potentially contaminated equipment with chlorine-containing cleaning solutions
References:
1 Martin S, Jung R. "Chapter 117. Gastrointestinal Infections and Enterotoxigenic Poisonings". Joseph T. DiPiro, Robert L. Talbert, Gary C. Yee, Gary R. Matzke, Barbara G. Wells, L. Michael Posey: Pharmacotherapy: A Pathophysiologic Approach, 7e: http://0-www.accesspharmacy.com.polar.onu. edu/content .aspx?aID=3188811. Accessed March 28, 2012.
2 Gerding DN, Johnson S. "Chapter 123. Clostridium diffi cile–Associated Disease, Including Pseudomembranous Colitis". Fauci AS, Braunwald E, Kasper DL, Hauser SL, Longo DL, Jameson JL, Loscalzo J: Harrison's Principles of Internal Medicine, 17e: http://0-www.accesspharmacy .com. polar.onu.edu/content.aspx?aID=2901764. Accessed March 28, 2012.
3 Cohen SH, Gerding DN, Johnson S, Kelly CP, Loo VG, McDonald LC, et al. Clinical practice guidelines for Clostridium diffi cle infection in adults: 2010 update by the Society for Healthcare Epidemiology of America (SHEA) and the Infectious Diseases Society of America (IDSA). Infect Control Hosp Epidemiol 2010;31:431-55.
4 Bartlett JG. Clinical practice: antibiotic-associated diarrhea. N Engl J Med 2002;346:334-39.

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