Fecal transplantation and molecular testing are among the new recommendations.
One of the most troublesome health care-associated infections that providers continue to struggle with in their health care facilities is Clostridium difficile (C. difficile). Luckily, advances have been made in the fight against the disease over the past few years, including the development of new diagnostic methods and treatments.
To reflect on these advancements, the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) worked together to release updated clinical guidelines for C. difficile in adults, and now, children. With these guidelines, health care providers can more effectively use the tools at their disposal to help improve patient outcomes.
The previous guidelines date back to 2010.
“These guidelines outline the preventive strategies for health care epidemiology and antibiotic stewardship,” Dale Gerding, MD, one of the authors of the guidelines told Contagion ®. “But beyond that, they also change the recommendations markedly for diagnosis and treatment of C. difficile. Both of which, if followed, will result in better identification of cases and better management of those cases.”
Currently, a C. difficile diagnosis is based on several factors, such as patient medical history, symptoms, and, of course, test results. However, when it comes to identifying an optimal method of diagnosis, researchers cannot seem to come to a consensus. In fact, the topic has become quite controversial in the field.
The reason for the controversy lies in the tests available, according to Dr. Gerding. Molecular tests (ie, nucleic acid amplification tests [NAAT]) are used by more than 70% of hospital labs, according to a press release on the new guidelines. “Immunoassay (IA) testing for toxins was the test available prior to the emergence of NAAT testing,” Dr. Gerding explained, “And now, we seem to be swinging back toward more toxin testing, so the guidelines are an attempt to reflect that.”
“If your hospital and laboratory personnel agree that only specimens from patients not receiving laxatives, who have at least 3 or more unformed stools in 24 hours are submitted for testing, then NAAT alone is an acceptable test modality,” he explained. However, if screening is not in place for laxative use or a number of unformed stools, then a test algorithm should be used.
“The algorithm just means that you use a test for C. difficile which is GDH, glutamate dehydrogenase, followed by a toxin test,” Dr. Gerding explained. “Or you could do GDH plus toxin and if the toxin is negative, you can follow that up with an NAAT, in addition.”
He added that, in Europe, some hospitals will use NAAT initially, a toxin test as a follow-up, and then report just the patients who are toxin-positive. “It’s a bit of a complex recommendation and I’m sure there will be a lot of questions about it,” Dr. Gerding admits. “On the other hand, there is at least some data in the literature that if you select patients who have significant symptoms, testing with NAAT is better at identifying those patients than just doing a toxin test.”
In addition to diagnosis, the guidelines were updated to include new recommendations for treatment, when warranted. One of the biggest updates? “We’ve eliminated metronidazole as a first-line treatment agent and we’ve recommended both vancomycin and fidaxomicin,” Dr. Gerding said. “The previous guideline was published before fidaxomicin even became available. And so, we’ve considered fidaxomicin for the first time in the guideline.”
“Now, the big issue around that is the cost of treatment. Metronidazole happens to be extremely inexpensive compared to vancomycin and fidaxomicin,” Dr. Gerding said. “And so, we did put a recommendation in that if it was difficult to access vancomycin or fidaxomicin, if access was limited—that can mean financial limitations as well—then metronidazole would be an acceptable treatment, only for non-severe C. difficile infections (mild to moderate infections), and that was about the only time that we felt that it would be appropriate to use it.”
The other big change is that fecal microbiota transplantation (FMT) has been included as a recommendation for patients who have experienced multiple recurrences of C. difficile infection. “We have included FMT as a recommendation for the first time,” Dr. Gerding said. “Antibiotic regimens are treating these patients with about 45% to 50% efficacy and FMT is up to 70% to 80% efficacy, so the difference there is probably about 20% to 25% in favor of FMT.”
The last major change that should be highlighted is that there are now recommendations on epidemiologic surveillance, diagnosis, and treatment of C. difficile in children—a population that the 2010 guidelines did not address.
Metronidazole is still being used to treat children with C. difficile. “In kids, we did not have the same kind of evidence that metronidazole is less effective than vancomycin as we saw in adults,” Dr. Gerding explained. “And so, metronidazole remains in the pediatric recommendations.”
It is known that colonization or the presence of C. difficile in young children is common; as such, it is clearly and strongly stated in the updated guidelines that those under 1 year of age are not recommended to get tested for the disease. “This is a new clear-cut statement of the fact that you should not test patients less than 12 months of age who have diarrhea. And, even toddlers 1 to 2 years of age should not be routinely tested unless other infectious and noninfectious guises of diarrhea can be excluded first,” Dr. Gerding said. “We’re trying to get away from testing very young children for C. difficile.”
With updated guidelines to reflect advancements made in the diagnosis and treatment of C. difficile, infectious disease specialists can better care for their patients, and hopefully, get a leg-up in the ongoing fight against C. difficile.