Exploring Different Methods to Prevent CDI Recurrence

Dale N. Gerding, MD, research physician, Medicine, at Edward Hines Jr. VA Hospital, discusses different methods used to prevent CDI recurrence.

Interview Transcript (modified slightly for readability):

“There’s a remarkably wide variety of ways [to prevent CDI recurrence], none of them completely successful, unfortunately. But antibiotics that we currently use—vancomycin and metronidazole, primarily—have reasonably high recurrence rates, probably [ranging between] 20% and 30%, so one of the ways to improve that is to use antibiotics that are better targeted to [Clostridium difficile] C. diff, that do not disrupt all of the other bacteria in the gut, so newer drugs like fidaxomicin, for example, are more effective at treating the disease and reducing recurrence.

And then, new drugs, as they’re being developed, are trying to replicate that to try to [cause less] C. diff [recurrence] than the current drugs [do]. We’re making progress, but there’s also been a number of failures along the road in those kinds of drugs. In just the last couple of years, we’ve had two antibiotics fail in phase 3 trials, unable to show noninferiority to vancomycin, the standard treatment.

[Another thing] that can be done [is] we can try to restore the microbiome so that it isn’t susceptible to C. diff infection [any longer]; so, that’s being done by fecal microbiome transplants and also by some derivatives of these microbiome preparations comprised of specific organisms that are obtained out of the microbiome and then are being re-administered to patients.

An alternative method is to try and improve the immunity of the patient, through what are called monoclonal antibodies, which are infused intravenously; they raise the level of antibodies to the toxins that are produced by the drug and doing that can reduce the risk of recurrence.

Also, in that same line, vaccines are being developed, which, ultimately, would be primary prevention methods and probably more effective as primary prevention than as prevention of recurrence because these vaccines take weeks to months to develop an immune response once you’ve been vaccinated; they also require three doses right now, and so, they’re kind of slow but should be effective once they’re on board. We don’t have any data yet as to how effective vaccines will be.

So, those are the methods; there’s one more, one that I work on, and that is a method that is simply a substitution of the toxigenic C. diff with a non-toxigenic C. diff that’s the same species of bacteria that lacks all the genes for making toxins, and if that gets in to your gut, it basically keeps out the toxigenic strains.”