Approach to amoebic colitis: Epidemiological, clinical and diagnostic considerations in a non-endemic context (Barcelona, 2007-2017)

Abstract

BACKGROUND: Amoebic colitis is the most frequent clinical manifestation of invasive intestinal infection due to Entamoeba histolytica and a common cause of diarrhoea worldwide. Since higher transmission rates are usually related to poor health and exposure to unhygienic conditions, cases reported in Europe usually involve immigrants and international travellers. The goal of this study was to characterise both the clinical and the epidemiological features of a European population diagnosed with amoebic colitis and then to evaluate the diagnostic tools and therapeutic options applied.

METHODS AND RESULTS: This was a retrospective observational study in which data from all patients diagnosed with amoebic colitis attending at the International Health Units of two tertiary referral hospitals, Germans Trias i Pujol University Hospital (Badalona, North Barcelona Metropolitan Area) and Vall d'Hebron University Hospital (Barcelona city) between 2007 and 2017 were analysed. During the study period 50 patients were diagnosed with amoebic colitis. Thirty-six (72%) were men, and immigrants accounted for 46% of all cases. Antecedents of any international travel were reported for 28 (56%), the most frequent destinations having been the Indian subcontinent, South and Central America and sub-Saharan Africa. Preexisting pathological conditions or any kind of immunosuppression were identified in 29 (58%) patients; of these, 13 (26%) had HIV infection-all of them men who have sex with men-and 5 (10%) had inflammatory bowel disease. Diarrhoea, abdominal pain and dysentery were the most frequently recorded symptoms of invasive amoebae. Diagnosis was made through microbiological study in 45 (90%) and/or histological identification of amoebae in colon biopsies in 10 (20%). After treatment with metronidazole (82%) or tinidazole (8%), all patients had good outcomes. Post-acute intraluminal treatment was indicated in 28 (56%).

CONCLUSIONS: Amoebic colitis should be suspected in patients with diarrhoea and compatible epidemiological risk factors (immigration, travelling abroad or men who have sex with men), especially if some degree of immunosuppression concurs. These risk factors must be taken into account in any diagnostic approach to inflammatory bowel disease (IBD), and active searches for stool parasites should be performed in such cases to rule out misdiagnosis or simultaneous amoebic infection. Treatment should include intraluminal anti-amoebic treatment in order to avoid relapse and prevent further spread of the disease.