An Update on Schistosomiasis

Abstract

Human schistosomiasis is caused by trematode parasites of the genus Schistosoma. Four species and two distinct clinical syndromes are relevant to humans, including S. haematobium, which is associated with urogenital schistosomiasis, whereas S. mansoni, S. mekongi, and S. japonicum are responsible for intestinal schistosomiasis. These flukes reside in the venous plexus of the human bladder and in mesenteric veins and release eggs that, when trapped in tissues, cause inflammation and fibrosis. More specifically, S. mansoni, S. mekongi, and S. japonicum can cause intestinal inflammation, hepatosplenic periportal fibrosis, portal hypertension, and esophageal varices that can bleed and cause death. In contrast, S. haematobium, a recognized carcinogenic organism, can drive bladder carcinoma and contribute to infertility and cervical cancer. Additionally, schistosomiasis can cause general anaemia, stunted growth, and cognitive impairment.

Despite the chronic complications associated with schistosomiasis, public awareness in areas of non-endemicity is limited, and travelers rarely consider risk of infection. We describe the diagnostics available in areas of endemicity, as well as in reference laboratories, to diagnose schistosomiasis in returning travelers or migrants to resource-rich locations.