Clostridium difficile infection: responses, relapses and re-infections.

Clostridium difficile infection is a common and potentially lethal complication of antibiotic usage. Since the aetiology of antibiotic-associated colitis was discovered 14 years ago, two antibiotics in particular, metronidazole and vancomycin, have been used to treat C. difficile infection. Studies comparing the efficacy of these antibiotics are reviewed. It is now apparent that many of the so-called 'relapses' of C. difficile infection following antibiotic treatment are, in fact, re-infections. Such findings have major infection control implications.