Infectious colitis

Abstract

Many infections of the gastrointestinal tract are transient, self-limiting illnesses, and thus are generally not confused with chronic non-specific inflammatory bowel disease (IBD). However, others, particularly those due to invasive enteropathogens which cause an ileocolitis, may mimic ulcerative colitis or Crohn's disease. It is thus essential to distinguish rapidly between these conditions since inappropriate use of corticosteroids or immunosuppressive drugs may adversely affect outcome. Similarly, delay in administering an appropriate antibiotic for a colonic infection may increase morbidity, including the hkelihood of developing complications. In the past, misdiagnosis of amoebiasis for example, has occurred with inappropriate use of corticosteroids which in some cases has resulted in colectomy and litigation. Some self-limiting colonic infections will resolve despite administration of steroids and mesalazine, but it is clearly inappropriate to commit an individual to lifelong maintenance therapy when further problems would not be expected following a single attack of infective colitis. Thus, precision regarding prognosis demands an accurate initial diagnosis of the etiology of an attack of colitis. Clinicians in the developing world, where the micro-organisms responsible for infectious colitis are endemic, are accustomed to routinely searching for an infectious cause for colitis before making a diagnosis of non-specific IBD. In the industrialized world for several decades the reverse situation has existed, with IBD always being the most likely diagnosis. However, in recent years there has been a steady increase in reports of intestinal infection to agencies responsible for the surveillance of infectious diseases in the United Kingdom and USA. In the UK there has been a steady increase in reports of Salmonella spp. and Campylobacter jejuni infections (Fig. 1) and a number of important outbreaks of enterohemorrhagic E. coli (EHEC) infection with a reported mortality of 1-2% and a relatively high incidence of serious complications such as the hemolytic- uremic syndrome. The continued increase in foreign travel has further contributed to the importance of infectious colitis in individuals living in the industrialized world [1], as has the increasing use of broad-spectrum antibiotics and the well-recognized association of antibiotic-related diarrhea and pseudomembraneous colitis due to infection with Clostridium difficile. Thus, despite the widespread implementation of public health measures to prevent transmission of intestinal enteropathogens in the industrialized world, intestinal infectious disease remains a significant problem which can be attributed to a number of factors including transmission of enteropathogens through food. Thus, clinicians must exercise increased vigilance in patients with diarrhea, particularly bloody diarrhea, and ensure that an appropriate search is made for an infective agent before a final diagnosis of non-specific IBD is made. © 2005 Springer Science+Business Media, Inc.