Clostridium Difficile Infection (CDI) is a Serious and Life-Threatening Disease
C. difficile is a human enteric pathogen which is transmitted by the fecal-oral route. It is distinguished by, first, its ability to form spores which are
highly resistant to normal environmental conditions, and, second, by its production of two toxins (TcdA and TcdB) which are highly pathogenic to
human colonic epithelium. The ability of these secreted toxins to induce colonic epithelial inflammation and damage by inducing cytokine and
chemokine production, inflammatory cell infiltration, and cell death results in the characteristic clinical picture of CDI.
In 2010, the Infectious Disease Society of America (IDSA) defined the clinical syndrome of CDI using a combination of both clinical and laboratory
criteria. The clinical criterion for the diagnosis is the presence of diarrhea manifesting as ≥3 unformed stools in ≤24 hours; the laboratory criterion
requires one of the following findings: (a) stool culture positivity for toxigenic C. difficile; (b) stool positivity for one or both C. difficile toxins; or
(c) colonoscopic visual or colonic histopathological findings of pseudomembranous enterocolitis.
The evolving epidemiology of CDI has recently (February, 2018) been reviewed by the IDSA and the Society for Healthcare Epidemiology of America
in their joint update on clinical practice guidelines for C. difficile infection. Although incidence of CDI appears to have declined in Europe over the
past decade, infection rates have plateaued but not fallen in the US. Using Centers for Disease Control and Prevention (CDC) surveillance data from
2011, estimate the US incidence of CDI to be 453,000 cases annually. Also of interest is the fact that, despite the availability of antibiotic therapy to
treat CDI, the estimated incidence of first recurrences of CDI following treatment was 83,000 cases per year, underlining the potentially serious
health consequences of the disease. The magnitude of CDI impact is further emphasized by the estimate that the disease may have resulted, in
2008, in an excess of $4.8 billion costs to US acute-care facilities.
|Microscopic (SEM) image depicts a large
grouping of rod-shaped
Clostridium difficile bacteria