IDSA, SHEA, Update Clostridium difficile Diagnosis, Treatment Guidelines

Brandon May

The update includes significant changes in the management of this infection and reflects the evolving controversy over best methods for diagnosis.

Clifford McDonald, MD

A recent clinical practice guideline update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) was published in Clinical Infectious Diseases last month, detailing new evidence-based insights into the diagnosis and treatment of Clostridium difficile (C. difficle).1

According to Clifford McDonald, MD, Associate Director for Science for Center for Disease Control and Prevention's (CDC) Division of Healthcare Quality Promotion, C. difficile remains one of the most common infections observed in the healthcare setting, affecting approximately 500,000 Americans each year.

C. difficile takes the life of 15,000 to 30,000 patients, and we want to see these infections reduced and eventually eliminated. The new guidelines focus on more effective treatment and diagnosis to help us save lives,” McDonald told MD Magazine.

One of the newest recommendations focus on diagnosis and includes testing patients only when they are suffering from significant or unexplained diarrhea. This includes patients who present with new-onset symptoms of ≥3 unformed stools within a 24-hour period. Considering a substantial number of patients with C. difficile are on a laxative, it’s imperative for clinicians to discern between patients who do and do not present with an actual case of the infection. In the event when no pre-agreed institutional criteria exist for patient stool collection, the guidelines now recommend using a stool toxin test in addition to a multistep protocol (eg, glutamate dehydrogenase [GDH] plus toxin; GDH plus toxin, arbitrated by nucleic acid amplification test [NAAT]; or NAAT plus toxin).

For testing, the IDSA-SHEA now recommend the use of a nucleic acid amplification test if “the medical and laboratory staff of a hospital have established criteria that assure the tested population is likely to have CDI.” In the event that this test is not feasible, the updated guideline now suggests a toxin immunoassay and molecular and/or antigen test can be used to identify C. difficile, which may subsequently minimize inappropriate treatment of false-positives.

Prevention strategies using patient isolation and a dedicated toilet is another recommendation in the updated guideline, based on moderate and high quality of available evidence. Although this recommendation may be implemented in current clinical practice, recent research continues to support this strategy for reducing transmission to uninfected persons residing in the same hospital.

Perhaps the most pronounced changes in the updated guideline relate to considerations regarding first-line antibiotic therapy.

“We are reducing metronidazole to second-line therapy and including fidaxomicin as another first-line therapy along with oral vancomycin,” commented McDonald.

Also, the new guidelines update their treatment recommendations for children and adults, suggesting different antibiotic combinations and strategies for new and recurrent infections.

Additionally, the new guidelines from the IDSA-SHEA provide another tool, fecal microbiome transplantation (FMT), in the clinician’s armamentarium of C. difficile treatment strategies as a proven alternative, particularly for patients with multiple episodes of recurrent C. diff and who do not take to the appropriate antibiotic therapy.

“Science is constantly evolving and bringing to light new methods of treatment, new diagnostic tests and new ways to improve the care of patients and reduce the spread of C. difficile,” McDonald concluded.


  1. McDonald LC, Gerding DN, Johnson S, et al. Clinical Practice Guidelines for Clostridium difficile Infection in Adults and Children: 2017 Update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA). Clin Infect Dis. 2018;66(7):987-994.