Schistosomiasis is a disease caused by infection with parasitic blood flukes. The three major species are Schistosoma mansoni (Africa and South America), S. japonicum (East Asia), and S. haematobium (Africa and the Middle East). The two minor species are S. mekongi (Laos, Cambodia) and S. intercalatum (West and Central Africa).
The parasites that cause schistosomiasis live in certain types of freshwater snails. Emergence of cercariae (the infectious form of the parasite) from the snail leads to contamination of the water. Individuals can become infected when skin comes in contact with contaminated water and is penetrated by cercariae.
The diagnosis of schistosomiasis will be reviewed here. The epidemiology, pathogenesis, clinical features, treatment, and prevention of these infections are discussed separately. (See "Epidemiology, pathogenesis, and clinical manifestations of schistosomiasis" and "Treatment and prevention of schistosomiasis".)
Clinical approach — The approach to diagnosis for returned travelers differs from the approach to diagnosis in endemic settings. Among returned travelers, serology is the most useful test. In endemic areas, serology can be useful but may not be readily available and does not reflect definitive evidence of current infection. In such cases, microscopy can be used to determine the infecting species and the burden of infection, although it is less helpful in the setting of early infection.
Diagnostic evaluation is warranted for patients with clinical manifestations suggestive of schistosomiasis in the setting of appropriate epidemiologic exposure; these are discussed further separately. (See "Epidemiology, pathogenesis, and clinical manifestations of schistosomiasis".)