Update on the Testing, Treatment, and Isolation of Patients with Clostridium difficile Infection (CDI)

Clostridium difficile, the leading cause of nosocomial enteric infection, is a gram-positive, spore-forming anaerobe. CDI can develop if the normal gastrointestinal flora is disrupted by antibiotic therapy and a person acquires toxin-producing C. difficile, typically via the fecal-oral route. Almost every antibiotic has been associated with CDI, and the use of antibiotics is the major risk factor for CDI. The incidence, severity and mortality due to CDI have been steadily increasing over the last decade. This is likely due to the spread of a new strain of C. difficile termed the NAP1/B1/O27 strain, which produces much higher levels of toxin than previous strains and is resistant to fluoroquinolone antibiotics. This strain has been detected at The Nebraska Medical Center, but the overall prevalence at The Nebraska Medical Center is unknown. The diagnosis of CDI has been difficult in the past as the most commonly used test, the toxin enzyme immunoassay (EIA), has suboptimal sensitivity (70-90%). Clinicians have attempted to overcome this poor sensitivity by repeat testing. Other tests are available for CDI such as culture, cytotoxic assay, tests for a “common antigen ” called glutamate dehydrogenase (GDH), and polymerase chain reaction (PCR) tests. In July of 2009, The Nebraska Medical Center introduced a new testing method for the detection of CDI utilizing detection of both GDH and toxins A and B