The epidemiology of Clostridium difficile infection is changing as a result of the epidemic spread of the hypervirulent North American Pulsefield type 1 strain. Clinicians are likely to encounter this disease more frequently than ever in their practice, and should be familiar with the updates in its diagnosis and treatment.

The majority of CDI still occurs in patients with well-recognized risk factors – antibiotic exposure and advanced age, hospitalization, or nursing-home residence. CDI has also been reported, however, in patients previously considered at low risk for the disease, such as healthy patients from the community [6], postpartum women, and perhaps patients on gastric acid suppressive medications [7]. The toxin enzyme immunoassay remains the main diagnostic modality in most clinical settings [6] but is rather insensitive, necessitating the submission of at least two specimens to improve the diagnostic yield. Prompt initiation of effective therapy can be crucial, especially in light of the rapid progression to fulminant disease observed with the NAP1 strain. Empiric treatment is now recommended immediately after specimen collection for patients with severe CDI [8,9], and the disease should be suspected in patients with unexplained leukemoid reaction even in the absence of diarrhea [10].

Metronidazole has been historically recommended as first-line CDI therapy primarily due to its low cost, its noninferiority to vancomycin, and its lower propensity for colonization with vancomycin-resistant enterocci and staphylococci [8]. Metronidazole remains a viable option for mild to moderate disease [1,9]. Recent data from observational studies and clinical experience suggest that metronidazole's efficacy may be decreasing [11], and a switch to oral vancomycin is indicated if at least some symptomatic improvement is not observed after 1–2 days of metronidazole treatment [9]. Oral vancomycin remains the preferred treatment for severe disease – defined in a recent randomized controlled trial [12] as the presence of pseudomembranous colitis or intensive care unit hospitalization, or the presence of two or more of the following: age >60 years, temperature >38.3°C, white blood cell count >15,000 cells/mm,³ albumin <2.5 mg/dl. As emphasized by Gould and McDonald in their review article [1], efforts must be directed to ensure drug delivery to the lumen of the colon in patients with decreased peristalsis and ileus [9].

Previously CDI was rarely a surgical disease, but recent experience is demonstrating otherwise. Emergency colectomy has been noted to improve survival in severely ill patients [13]. The clinical challenge is in identifying the patients warranting colectomy and its timing. In patients with suspected severe CDI, and those with ileus or toxic megacolon, an early surgical consultation should be obtained [9,13].

CDI = Clostridium difficile infection; NAP1 = North American Pulsefield type 1.

The authors declare that they have no competing interests.