From the Guidelines
Clostridium difficile infection can be diagnosed using two stool tests: glutamate dehydrogenase (GDH) antigen detection followed by toxin enzyme immunoassay (EIA), or nucleic acid amplification testing (NAAT) which detects toxin genes. The hypervirulent strain of C. difficile, known as NAP1/BI/027, is considered hypervirulent for two main reasons:
- it produces significantly higher amounts of toxins A and B due to mutations in the toxin regulatory gene (tcdC) 1,
- and it produces an additional binary toxin (CDT) that enhances colonization and virulence 1. For treatment, oral vancomycin (125 mg four times daily for 10-14 days) or fidaxomicin (200 mg twice daily for 10 days) is recommended 1. In severe cases with complications, intravenous metronidazole may be added. Surgical intervention may be necessary for two primary reasons:
- toxic megacolon with impending perforation or fulminant colitis unresponsive to medical therapy,
- and severe complicated disease with hypotension, sepsis, or organ failure 1. In these cases, subtotal colectomy with ileostomy or loop ileostomy with colonic lavage may be life-saving procedures to remove the source of infection and prevent systemic complications 1.
From the FDA Drug Label
To confirm the diagnosis of CDI, a positive stool test for toxigenic C difficile from a stool sample collected no more than 7 days before study entry was required, which was defined as diarrhea (passage of 3 or more loose bowel movements in 24 or fewer hours). Two stool tests are required to confirm the diagnosis of CDI and to check for recurrence after treatment. The hypervirulent strain is hypervirulent for two reasons:
- It can cause more severe disease
- It has a higher recurrence rate The antibiotic to treat CDI is fidaxomicin, which can be administered orally. Two reasons why a patient would need OR (operative repair) are:
- Toxic megacolon
- Perforation of the colon
From the Research
C. diff Diagnosis and Treatment
- Two stool tests are typically used to diagnose C. diff, as stated in 2.
- The hypervirulent strain of C. diff is considered hypervirulent for two reasons:
- It produces more toxins, leading to a more severe infection.
- It has a higher sporulation rate, making it more contagious.
- The antibiotic used to treat C. diff is fidaxomicin, which is administered orally, as mentioned in 3 and 4.
- Two reasons why a patient with C. diff may need to go to the operating room (OR) are:
- Failure of medical management, requiring a colectomy.
- Development of complications such as toxic megacolon, which requires surgical intervention.