Schistosoma spp.

Schistosoma mansoni. Egg in Kato/Katz fecal smear (unstained, high power). The appearance of S. mansoni eggs in a cellophane-covered thick smear preparation is different from that seen in ordinary fecal smears. As shown here, the large size of the egg makes it easy to see, but because of the thickness of the smear the spine frequently may be oriented in other than a lateral aspect.