CDC Cercarial dermatitis

(1)

Eggs are passed in feces.

(2)

Eggs hatch and liberate miracidia.

(3)

The parasite develops in a molluscan intermediate host.

(4)

Adult schistosomes in definitive host

Cercariae penetrate the skin of definitive hosts and migrate to blood vessels to complete the cycle.

(5)

Humans are exposed to the dermatitis-producing cercariae.

Though some schistosomes of mammals cause cercarial dermatitis, the vast majority involved are of_______-,and many of which exhibit relatively low specificity among bird hosts.

For example, Trichobilharzia spp. are often associated with anseriform birds (e.g. ducks, geese) and Austrobilharzia spp. with many species of anseriforms, wading birds, and seabirds. Gigantobilharzia spp. have been identified in goldfinches, starlings, pelicans, cardinals, crows, canaries, and more.

avian origin

Among the more well-described dermatitis causing mammalian schistosomes, _______________ is found in dogs and raccoons

Heterobilharzia americana

__________ normally infects ruminant livestock. Snail intermediate hosts are diverse and will depend on the parasite species and the habitat of the definitive host

Schistosoma spindale

Cercaria of Austrobilharzi

Cercarial dermatitis known as

swimmer's itch