c difficile

A Bad, Bad Bug: An Update on C Difficile

Gregory W. Rutecki, MD 

In 2011, the number of serious healthcare-associated infections caused by the germ Clostridium difficile was estimated to be nearly 1.5 million. Out of those cases, 29,000 patients died within 30 days of the initial diagnosis. Most at-risk are those people using antibiotics and being treated for a medical condition.1 

From 2001 to 2005, the number of C difficile hospital-discharge diagnoses more than doubled.2 The cost to our healthcare system? More than $1.5 billion.1 

Deeming this condition ubiquitous is an understatement. This month’s Top Paper2 provides a valuable update on the diagnosis and treatment of C. difficile.

Clostridium difficile Infection: What You Need to Know
Researchers Discover How C. difficile Disrupts the Gut

For the primary care provider, these attention-getting facts will surely resonate—and make a difference in how C. difficile is managed in the healthcare setting.  

Test once for the toxin and not repeatedly. A systematic review demonstrated that 91% of positive C difficile results occur after the first test. The probability of a second or third test being positive after 2 negatives is <2.5%.

The treatment of C difficile depends on the severity of disease. There is no significant difference in cure rates for mild C difficile infections between metronidazole and vancomycin. But, with severe disease, vancomycin has a 97% cure rate versus 76% with metronidazole. The Top Paper2 has a number of severity formulas using age, white blood cell count, and abdominal tenderness.   

There are risk factors for metronidazole failure. This is particular true in certain conditions: 60 years or older, experiences fever, hypoalbuminemia, leukocytosis, ICU stay, and abnormal CT scan findings.

Vancomycin is the preferred first choice for severe or complicated C difficile infections. Prescribe 125 mg orally, 4 times daily for 10 to 14 days. Rectal vancomycin may not reach the entire affected area.    

Either metronidazole or vancomycin can be used for a first recurrence. Any subsequent recurrences should be treated with vancomycin.     

A new treatment—fidaxomici—was approved in 2011. In some studies, it is not inferior to vancomycin.

Not all medications are considered equal. When other antibiotics cannot be discontinued despite the presence of C difficile infections, fidaxomicin has higher cure rates than vancomycin.

Fecal transplants have promise. C difficile symptoms resolved in 94% of patients who received 5 days of vancomycin followed by 1 to 2 treatments with healthy fecal microbiota transplants. The numbers were only 31% for 14 days of vancomycin alone.

It seems that every practitioner has to confront the epidemic of C difficile. This paper has a number of helpful hints to inform our diagnosis and treatment. ■

Gregory W. Rutecki, MD, is a physician at the National Consult Service at the Cleveland Clinic. He is also a member of the editorial board of Consultant. Dr Rutecki reports that he has no relevant financial relationships to disclose.


1. Lessa F, Mu Y, Bamberg W, et al. Burden of Clostridium difficile infection in the United States. N Engl J Med. 2015;372(9):825-834. 

2. Bagdasarian N, Rao K, Malani PN. Diagnosis and treatment of Clostridium difficile in adults. Am J Med. 2015;313(4):398-408.