The infective stages of the Schistosomes and other trema todes, which are free living in water. In some trematodes (e.g. Fasciola), the cercariae develope into metacercariae for infection.
A syndrome characterised by allergic symptoms and involving the respiratory tract (i.e. fever, cough, rash and marked eosinophilia) sometimes seen in patients who have had exposure to a large number of schistosome cercariae, especially Schistosoma japonicum, sometimes S. mansoni, rarely S. haematobium. Sydrome occurs during the invasive stage of schistosomiasis from the time of cercarial penetration of the skin to the time of early egg laying in the veins.... katayama syndrome
n. (pl. cercariae) the final larval stage of any parasitic trematode (see fluke). The cercariae, which have tails but otherwise resemble the adults, are released into water from the snail host in which the parasite undergoes part of its development. Several thousand cercariae may emerge from a single snail in a day.... cercaria
n. any of the parasitic flatworms belonging to the group Trematoda. Adult flukes, which have suckers for attachment to their host, are parasites of humans, occurring in the liver (liver flukes; see Fasciola), lungs (see Paragonimus), gut (see Heterophyes), and blood vessels (blood flukes; see Schistosoma) and often cause serious disease. Eggs, passed out with the host’s stools, hatch into larvae called *miracidia, which penetrate an intermediate snail host. Miracidia give rise asexually to *redia larvae and finally *cercariae in the snail’s tissues. The released cercariae may enter a second intermediate host (such as a fish or crustacean); form a cyst (*metacercaria) on vegetation; or directly penetrate the human skin.... fluke
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