Schistosomiasis: a rare cause of gastrointestinal bleeding

To the Editor: A 35‐year‐old man born in Dire Dawa, Ethiopia, with childhood exposure to swimming in rivers, migrated to Australia 18 years ago. He presented with recurrent gastrointestinal bleeding. His index gastroscopy revealed portal hypertensive gastropathy and large oesophageal varices with high risk stigmata of recent bleeding requiring banding. Abdominal ultrasonography and transient elastography excluded liver cirrhosis.

Six weeks later, he re‐presented with recurrent severe haematemesis associated with dark maroon rectal bleeding. Repeat urgent gastroscopy and flexi‐sigmoidoscopy revealed oesophageal varices without active bleeding. On sigmoidoscopy, a large amount of dark blood was seen, presumed to be related to rapid transit from recent oesophageal variceal bleeding. In the next 48 hours, a repeat colonoscopy was performed. Colonoscopy identified yellowish nodules throughout the colon with diffuse telangiectasia (Box, A and B). Mucosa was oedematous and friable. Aphthous ulcers were seen in the transverse colon and biopsies were obtained. No polyps or focal source of colonic bleeding were evident.

Histopathology confirmed the presence of cystic ova resembling Schistosoma in the lamina propria immediately adjacent to crypts. Although classical granuloma formation was absent, aggregation of eosinophils was seen around a ruptured ovum (Box, C and D). Indirect assay via serology testing was positive for Schistosoma mansoni antibody (titre of 1:640). His eosinophil count was normal and stool microscopy was negative. He was treated with praziquantel. Four months later, a follow‐up gastroscopy revealed stable appearance of grade 1 oesophageal varices without high risk features. Routine variceal surveillance had been organised but not further colonoscopies.

Schistosomiasis affects over 200 million people worldwide but is not acquired in Australia. In a national survey in Ethiopia, 37.3 million individuals were living in endemic areas.1 Schistosoma mansoni is the commonest species to cause intestinal and hepatic schistosomiasis. In the 2016 national census, there were 11 795 people in Australia who were born in Ethiopia, 64.3% (7584) of whom were Australian citizens.2 Most screening data for schistosomiasis in Australia are based on African refugees, with 37% in Newcastle, 38% in Hobart and 12% in Melbourne.3 Despite anecdotal knowledge, there are no published cases of non‐cirrhotic portal hypertension related to schistosomiasis in Australia. As a multiracial country with high immigration and tourism, increased recognition in Australia is paramount.

Box – Colonoscopy showing widespread yellowish nodules (arrows) with oedematous and friable mucosa (A) and diffuse telangiectasia (B); and histopathology showing aggregation of eosinophils surrounding a Schistosoma ovum(C) and a cross‐sectional image of a Schistosoma ovum (D)

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