Health care-associated infections—those that occur during the time when patients are receiving medical care—have largely decreased in recent years because of an increased emphasis on prevention and infection control. But one infection, Clostridium difficile, which causes diarrhea and is associated with 14,000 deaths each year in the U.S., has been difficult to tame. It is now, according to a recent report from the Centers for Disease Control and Prevention (CDC), at historically high levels.
Toxins produced by the bacterium C. difficile are the most common cause of diarrhea in people who develop diarrheal symptoms while hospitalized. The CDC Vital Signs report states that those most at risk for contracting C. difficile are people, especially older adults, who take antibiotics and also get medical care. Antibiotics that are used to kill bacteria that cause infections (pathogens) can also kill bacteria that are part of the natural environment of the digestive tract (normal flora). This can upset the balance and result in the overgrowth of antibiotic-resistant C. difficile, which is typically spread from contaminated surfaces or from a health care provider's contaminated hands. Hospitals, nursing homes, and doctor's office and clinics can all be sources of the infection.
Given the current high rate of C. difficile infections, the CDC recommends that physicians prescribe antibiotics very carefully and test their patients for the infection if they develop diarrhea while on antibiotics or within several months of taking them. If the infection is confirmed, the patient can be isolated and treated to reduce the spread of C. difficile in a health care setting, such as the hospital or nursing home. For patients at home, precautions can also be taken to avoid infecting others. These include frequent and thorough hand washing with soap and water, disinfecting surfaces in bathrooms, kitchens, etc. with a dilute bleach solution, or even limiting the use of one bathroom to the infected person when possible.
There are a number of tests available to detect toxin-producing C. difficile. Detection of C. difficile toxin is problematic because the toxin breaks down at room temperature and may not be detected if the stool sample is not transported quickly to the laboratory. Some tests are very sensitive but can take days to complete. Other tests are rapid but may not be sensitive enough for definitive results. So, a combination of tests may be best to help make a diagnosis.
Since there is currently no one test that is fast, widely available, and sensitive and specific enough, the Society for Healthcare Epidemiology of America and the Infectious Diseases Society of America recently recommended a two-step testing process: 1) test stool samples of symptomatic patients for glutamate dehydrogenase, an enzyme produced by C. difficile, which is a sensitive test for the presence of the bacteria, and 2) follow up any positive test results with a specific test to determine if the toxin that causes damage to the colon is present, since not all C. difficile may produce the toxin.
Effective testing protocols partnered with appropriate treatment and isolation of affected patients can help reduce the number of infections. There are also several steps people can take to help prevent C. difficile. The following is advice from the CDC:
- Take antibiotics only as prescribed by your doctor.
- Tell your doctor if you have been on antibiotics and develop diarrhea within a few months.
- Wash your hands after using the bathroom.
- Try to use a separate bathroom if you have diarrhea and be sure a bathroom is cleaned well if someone with diarrhea has used it.
On this site
Tests: Clostridium difficile and C. difficile toxin testing
In the News: Clostridium difficile Guidelines Address Testing Strategies (2010)
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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.
Centers for Disease Control and Prevention. Vital Signs – Making Health Care Safer: Stopping C. difficile Infections. March 2012. Available online at http://www.cdc.gov/VitalSigns/HAI/ through http://www.cdc.gov. Accessed May 2012.
(July 1, 2009) APIC. Clostridium Difficile. Available online at http://www.apic.org/For-Consumers/IP-Topics/Article?id=clostridium-difficile through http://www.apic.org. Accessed May 2012.