Q&A with Fight C. diff Gala Honoree Dr. Dale Gerding

Q: What led you to focus your research on C. diff infections?

A: I was the hospital epidemiologist in 1980 when the stool toxin test for C. diff first became available. When our lab started using the test we had so many positives that we thought something was wrong with the test. It turned out the test was fine, but we were in the midstof a C. diff outbreak and did not realize it until we started testing. From there we quickly expanded to doing careful epidemiology of these infections, developed molecular typing methods, and began to do clinical treatment trials. We are still at it.

Q: Why have C. diff infections become more frequent?

A: The answer to this is not completely known, but it is generally agreed that increased antibiotic use in the 1990s, particularly fluoroquinolones and cephalosporins, led to the emergence of a new more virulent strain of C. diff called NAP1/BI/027 in the 21^stcentury that quickly became the dominant C. diff infection strain in the US, Canada, and Europe. It has proven difficult to treat this strain and because it is resistant to both fluoroquinolone and cephalosporin antibiotics it can spread readily among patients taking these antibiotics. In more recent years rates of C. diff infection are slowly declining in the US and have markedly declined in the UK associated with a decline in the number of infections caused by NAP1/BI/027.

Q: What are the biggest challenges in treating C. diff infections?

A: For over 20 years it was agreed that metronidazole and vancomycin were both effective in treating C. diff, but with the advent of the epidemic NAP1/BI/027 strain in the 21^st century it eventually became apparent that metronidazole was no longer as effective as vancomycin. As a result, new C. diff guidelines in the US no longer recommend metronidazole for treatment of any C. diff infection. The biggest challenge currently is to find antibiotics or other means to treat C. diff episodes and reduce the current 15% to 25% recurrence rate seen with fidaxomicin and vancomycin, the two primary antibiotic treatments for C. diff infection.

Q: What is your advice to physicians treating C. diff Infections?

A: Follow the current C. diff IDSA/SHEA Guidelines when treating and be sure to caution patients to avoid antibiotic exposure for non-C. diff infections if at all possible. This will help reduce the recurrence rate of C. diff. For patients who have suffered multiple recurrences of C. diff infection, seek help from GI or infectious disease specialists who have experience managing these patients as these recurrences can be very challenging.

Q: What can people do to protect themselves and their families against C. diff infections?

A: Patients should be aware that the greatest risk for C. diff infection is antibiotic administration. If they are prescribed an antibiotic for an infection that has marginal or no antibiotic indication such as acute bronchitis, common colds or sinusitis, they should question whether it can be managed without an antibiotic. Antibiotics may be life-saving for the types of infection they are intended, but they have side effects that include damage to the normal protective“good” bacteria in the gut that make patients susceptible to C. diff. Always question whether an antibiotic is really needed. Do not accept the premise that an “antibiotic can’t hurt” because it can really hurt if it results in a C. diff infection