Species involved: Schistosoma mansoni and Schistosoma haematobium
Pathogenesis: Eggs are deposited in the intestinal wall where they elicit a granulomatous inflammatory reaction with fibrosis.
Sites: anywhere in the bowel wall from the duodenum to the colon
Clinical findings:
(1) afebrile dysentery which may or may not be bloody
(2) nausea and/or bloating
(3) abdominal pain
(4) rectal tenesmus
(5) hepatosplenomegaly
(6) meteorism (gas in the bowel or abdomen)
(7) constipation
(8) bowel obstruction
(9) intermittent rectal bleeding
Endoscopic appearance may include inflammation, mucosal thickening and inflammatory polyps. It may mimic changes seen in idiopathic inflammatory bowel disease.
Laboratory findings:
(1) negative stool culture for pathogenic bacteria
(2) presence of Schistosome eggs in stool and/or mucosal biopsies
(3) variable eosinophilia
(4) positive serologic test for anti-schistosomal antibodies
(5) positive PCR
