Schistosomiasis.

摘要

For most helminth infections, morbidity is concentrated in endemic settings and associated with heavy exposure. Helminths, with the notable exception of Strongyloides, cannot complete their life cycle in man so worm burden is related to the extent of environmental exposure. Global morbidity related to schistosomi-asis is predominantly restricted to rural and semi-urban communities where freshwater exposure is a feature of daily life, affording the parasite repeated opportunities for infection and thus generating a cumulative worm burden in the human host. Manifestations of such heavy schistosome infections are occasionally seen in non-endemic settings among migrants from these communities. Diagnosis is usually straightforward.