Clostridium difficile is now established as the most common nosocomial
enteric pathogen causing pseudomembranous colitis, antibiotic-associa
ted colitis and antibiotic-associated diarrhoea. Antibiotic therapy is
the most important risk factor in colonization and infection with C.
difficile. However, other factors are involved such as age and underly
ing illness. The introduction of reliable typing and fingerprinting me
thods has demonstrated hospital acquisition and cross-infection with C
. difficile and has been important in improving our understanding of t
he epidemiology and pathogenicity of C. difficile.