Medical Parasitology Cestoda

Cestodes classified….. • Phylum: Platyhelminthes • Class: Cestoidea • Subclass Eucestoda • Order Pseudophyllidae eg D. latum • Order Cyclophyllidae eg Taenias LIFE CYCLE PATTERNS 1. Pseudophyllidae type • Scolex provided 2 grooves - bothrium • Need two intermediate hosts • aquatic crustaceans • fish or other vertebrate animals • Life stages eggcoracidium  procercoid plerocercoid (sparganum)  adult worm • Spirometra mansoni – cause sparganosis • Diphylobothrium latum – accidental infection in humans copepod 2. Cyclophyllidae • Scolex provided 4 suckers sometimes supplemented with/without circular of hooks • Need one intermediate host only -- usually mammals • Life stages egg hexacanth metacestode stage  adult worm. • Taenia solium • Teania saginata • Echinococcus granulosus • E. multilocularis • Hymenolepis spp