Invasive amoebiasis complicating iflammatory bowel disease

Introduction Amoebiasis, which is caused by the intestinal protozoan Entamoeba histolytica, is a ubiquitous parasitic infection affecting approximately 10% of the world's population and causing more deaths every year (100,000 deaths) than any other parasitic infection, with the exception of malaria and schistosomiasis [1–3]. Most individuals with an E. histolytica infection are asymptomatic, but some develop severe invasive disease, such as amoebic colitis. Other manifestations, such as pulmonary, cardiac or brain involvement, are rare. Intestinal amoebiasis can probably also present as a chronic, non-dysenteric syndrome of diarrhoea, weight loss, and abdominal pain that can last for years and mimic inflammatory bowel disease. Fulminant colitis with bowel necrosis leading to perforation and peritonitis occurs in only about 0.5% of cases, but it is associated with a mortality rate of more than 40%. Patients with invasive amoebiasis living in the United Kingdom and other developed countries generally acquire the infection in another country in which the pathogenic species is endemic. Areas that have high rates of amoebic infection include India, Africa, Mexico and parts of Central and South America. Infection with pathogenic E. histolytica is not a common cause of travelers' diarrhoea, and gastrointestinal infection is uncommon in travelers who have spent less than one month in endemic areas. Despite the availability of sophisticated investigative procedures, differentiating invasive colonic amoebiasis from idiopathic inflammatory bowel disease (IBD) may be difficult. This case is presented to remind clinicians of the similarities in the clinical presentation and endoscopic features of these two conditions, and to highlight the difficulty in differentiating them.