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January/February 2012
Combating Clostridium DifficileBy Jessica Girdwain Patients of advanced age with antibiotic exposure, GI surgery, long institutional stays, or serious underlying illness are at increased risk of acquiring this bacterial infection. To call Clostridium difficile (C diff), a disease that primarily threatens older patients in hospitals and elder care facilities, a thorn in the side of healthcare workers would be an understatement. The virulent bacterial infection that causes severe diarrhea is quick to spread and difficult to remove from hospital environments, and its incidence has exploded in the last decade. In fact, according to the Centers for Disease Control and Prevention (CDC), it has caused more deaths in the United States than all other intestinal infections combined. While those infected are often only mildly sick, C diff can advance to a point where it “irreversibly damages the colon,” says William A. Petri, Jr, MD, PhD, a professor of internal medicine and pathology and the associate director of microbiology at the School of Medicine at the University of Virginia. In severe cases, C diff may cause sepsis, multiorgan failure, intestinal perforation, or death. It’s a disease that traditionally affects adults over the age of 65, perhaps due to a weakened immune system. “What’s at least a possibility is that they don’t develop a good immune response to the C diff toxins so they’re more prone to get infected in the first place. Add to that the fact that they can’t develop a good immune response, and they’re more likely to experience a recurrence of the infection,” says Stuart Cohen, MD, coauthor of “Clinical Practice Guidelines for Clostridium difficile Infection in Adults” published in the May 2010 issue of Infection Control & Hospital Epidemiology. Additionally, older adults are more likely to suffer from other medical illnesses, such as heart disease and emphysema so once they get an infection like C diff, it’s more likely to become severe, and “an elderly person doesn’t respond as well to aggressive infections, making outcomes worse,” says Cohen. Origin of the Infection Another study conducted by Winthrop-University Hospital in Mineola, New York, “An ‘On-Admission’ Prediction Model of Disease Severity in Clostridium difficile Infection,” suggests that clinicians pay particular attention to patients at the time of CDI diagnosis because the nursing home residence factor apparently serves as a significant predictor of outcomes. In addition to the confined living quarters and daily group activities among nursing home residents, this population is more likely to be taking antibiotics, increasing the likelihood of contracting a more severe strain of the disease, according to researchers. Skyrocketing Rates Several theories have emerged to explain what’s responsible for the uptick. One is the overuse of antibiotics, including fluoroquinolones. “C diff flourishes where other bacteria get killed, so antibiotics we use on infections, like community-acquired pneumonia, kill normal gut flora. C diff comes in and is then able to grow like crab grass,” says Rebekah Moehring, MD, an infectious disease fellow at Duke University School of Medicine in Durham, N.C. “The biggest risk factor for your patients acquiring C diff is antibiotic use—and judicious use is critical. One thing I often hear about in long term elder care facilities is that when a resident’s urine looks cloudy, the first thing that happens is a doctor prescribes antibiotics before evaluating if it’s truly an infection,” Cohen says. He notes that the prudent use of antibiotics is something physicians should be aware of in efforts to control C diff rates. Such efforts are among the reasons many hospitals are instituting antibiotic stewardship programs led by infectious disease physicians to help doctors more appropriately use antibiotics. Another factor responsible for the increase is a new strain of the bacteria that has rapidly emerged in the last decade, as noted by the CDC. In 2004, NAP1 was discovered and linked to several hospital outbreaks. Known to be more virulent than other strains, it produces more exotoxins along with an additional toxin called a binary toxin. “This new strain produces 10 times the toxins than previous strains,” says Petri. When it causes sickness, these cases are more severe, creating a greater number of complications, according to Petri. Treatment of this strain is often more difficult, as it is resistant to fluoroquinolones, says Moehring. She says more CDI cases are being reported simply because doctors are aware of the condition and looking for it. The increased awareness, which is good, increases the likelihood that doctors will properly identify the symptoms and quickly test and confirm the diagnosis. “We also think that improved testing identifies more cases, and this may also contribute to the increase in C diff,” notes Moehring. An Ounce of Prevention • Healthcare providers should wear gowns and gloves to create a barrier between the worker and the environment and prevent transmission from practitioners to other patients via hands or other parts of the body. • Promptly identify patients with C diff. Patients will exhibit clinical symptoms (watery diarrhea, fever, nausea, abdominal pain or tenderness, loss of appetite) and test positive for the C diff organism or its toxin. • Place patients with C diff in private rooms or isolate them with other patients with C diff infections. However, “The time needed to keep the patients separated hasn’t been definitively answered. It’s important to know that even when the patient is starting to feel better, we can still detect C diff in stools,” says Moehring. It’s best to wait until a patient is discharged from the hospital or, in the event a patient is spending an extended time period in the hospital, doctors should wait until he or she has completed treatment and is symptom free, although “it’s a different situation for every patient,” Moehring says. • Wash hands with soap and water before and after interacting with each patient. Avoid alcohol-based solutions, as these don’t readily kill C diff spores. • Disinfect hospital rooms properly. As a spore-forming organism, C diff can remain on surfaces, such as bed rails or counters, for an extended period of time. “It doesn’t die and just sits there for days and days,” says Moehring. These spores are also resistant to a lot of antiseptics and hospital-grade disinfectants, making them a challenge to remove. The solution: Bleach is best, Moehring says. (Researchers are working to develop a better way to clean hospital rooms. For example, Duke University School of Medicine is set to begin testing on a promising new way to disinfect rooms using an ultraviolet light device.) CDI Diagnosis Of the 40 hospitals affiliated with the Duke Infection Control Outreach Network, about seven or eight use PCR testing, says Moehring. “While it takes more lab expertise, it does perform better, and I suspect more facilities will start to move toward using it,” she says. Before testing even begins, Cohen says doctors should be on alert for patients who are highly suspect for contracting the infection. “If an older patient is seriously ill with diarrhea, you have to treat them before you receive the results. The sooner you do that, the more likely you’ll get a good outcome,” he says. Additionally, many patients show an atypical presentation of CDI. In some, Cohen notes, they may have an ileus. “Many times, doctors should consider C diff even if their patient does not get diarrhea.” Treatment Options A 2011 study published in The New England Journal of Medicine compared fidaxomicin with vancomycin. Patients received 200 mg of fidaxomicin or 125 mg of vanomycin orally for 10 days. While both antibiotics cured patients with equal efficacy, those on fidaxomicin experienced a significantly lower recurrence rate (15.4%) than those on vanomycin (25.3%). Although fidaxomicin is certainly promising, Moehring says she doesn’t expect the drug to take over as the primary form of treatment any time soon. “It’s very expensive right now. Since the research has shown that it’s equivalent in terms of efficacy in the first occurrence, it might make a good choice for patients with recurring infections,” she says. “We’ll need to see more data, and they’ll have to make it more practical to use in terms of price in order to see widespread use.” While antibiotics may be a first-line treatment, many CDI cases are recurring and may require additional procedures. One such option, fecal transplant, takes stool from a healthy donor and replaces the colon’s contents in patients with C diff. However, the procedure is appropriate primarily for treating relapse. “About 250 cases have been reported, and the procedure is almost universally successful,” notes Bartlett. It’s an important procedure with which physicians should become familiar because patients often come into the office asking about these transplants after doing Internet research, he says. Recent studies presented at the American College of Gastroenterology’s annual meeting attest to fecal transplant’s effectiveness. One study conducted at the Digestive Health Center at Integris Baptist Medical Center in Oklahoma City found that symptoms of C diff were resolved in 98% of patients who underwent the procedure. But doctors should make patients aware that a fecal transplant is appropriate only when the standard method for treating relapse fails, he notes. The number of clinicians performing the procedure is limited so Bartlett recommends healthcare practitioners know where in their area it’s available. A new surgical procedure is bringing hope to the 10% of severely sick patients who, because of CDI, require a total colectomy. In a recent study published in Annals of Surgery, the authors performed an ileostomy in 42 patients and compared the results with 42 patients who had previously undergone a colectomy. Of the ileostomy group, eight patients died compared with 21 in the colectomy group. Though researchers say that randomized trials are needed to confirm their results, Bartlett says the surgery is an exciting advancement. “The good news about the procedure is that it allows the patient to keep their colon,” he says. The Future for CDI Regardless, experts continue to advance the field to prevent future hospital outbreaks. “The series of new drugs and strategies coming down the pipeline are set to change the whole field of C diff in five years,” says Cohen. One area on which infectious disease specialists are keeping a close eye is the transfer of CDI into the community. “People are getting C diff who had no exposure to healthcare facilities or hospitals. It’s concerning for everyone because the infection is getting out,” says Moehring. In addition, doctors remain unaware of how it is traveling into the community, though future research will determine where it’s coming from and how to contain this dangerous infection. — Jessica Girdwain is a Chicago-based freelance writer who has contributed health-related articles to several national magazines.
Antacids May Increase CDI — Source: Clinical Infectious Diseases
C Diff Lengthens Hospital Stays For the study, published December 5 in CMAJ, researchers analyzed information on nearly 137,000 hospital admissions in Ottawa, Canada, over the course of seven years. Of those admissions, 1,393 patients became infected with C diff and spent 34 days in the hospital compared with just eight days for those who did not have the infection. However, patients with C diff generally had more serious illnesses, which the researchers took into account. They then calculated that acquiring the infection actually lengthened hospital stays by an average of six days. “We believe our study provides the most accurate measure yet of the impact of hospital-acquired C difficile on length of hospital stay,” study author Alan Forster, a senior scientist at the Ottawa Hospital Research Institute and an associate professor at the University of Ottawa, said in a press release about the study. He noted that new tools to collect hospital data and provide more accurate information are boosting infection-prevention efforts. — Source: CMAJ
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