PARA_Finals_Lec/Lab: Cestodes

Cestodes

Also known as Tapeworms

Developmental stages of cestodes

Egg, Larva, Adult

General body appearance of cestodes

Flat, ribbon-like, chalk-white

Cestodes reproductive characteristic

Hermaphrodite

Cestodes digestive system

Absent

Cestodes circulatory system

Absent

Mode of food acquisition in cestodes

Osmosis

Excretory system of cestodes

Flame cells

Nervous system of cestodes

Ganglia

Scolex

Most anterior part; attachment to intestinal mucosa

Neck

Region for growth

Proglottid forms

Immature, Mature, Gravid

Mature proglottid

Contains male and female reproductive organs

Gravid proglottid

Contains eggs

Self-fertilization

Mode of reproduction of hermaphroditic cestodes

Diagnostic form of most cestodes

Eggs in stool

Pseudophyllidean

Fake tapeworm

Cyclophyllidean

True tapeworm

Scolex of Pseudophyllidean

Spoon/almond/spatula-shaped with bothria

Bothria

Sucking grooves

Scolex of Cyclophyllidean

Quadrate with 4 cup-like suckers

Proglottids of Pseudophyllidean

Anapolytic (with uterine pore)

Proglottids of Cyclophyllidean

Apolytic (no uterine pore)

Egg of Pseudophyllidean

Oval, operculated

Egg of Cyclophyllidean

Spherical, non-operculated

Intermediate host of Pseudophyllidean

Two (2)

Intermediate host of Cyclophyllidean

One (1)

Diphyllobothrium latum, Group?

Group: Pseudophyllidean

Diphyllobothrium latum disease

Diphyllobothriasis

Common name of D. latum

Fish tapeworm / Broad tapeworm

Habitat of D. latum

Small intestines

Portal of entry of D. latum

Mouth

1st intermediate host of D. latum

Crustaceans (Cyclops, Diaptomus)

2nd intermediate host of D. latum

Freshwater fish

Infective stage of D. latum

Plurocercoid larva

Diagnostic form of D. latum

Unembryonated egg

Mode of transmission of D. latum

Ingestion of raw/improperly cooked freshwater fish

Egg of D. latum

Operculated with abopercular knob

Scolex of D. latum

Contains bothria

Characteristic uterus of D. latum

Rosette appearance

L1 of D. latum

Coracidium

L2 of D. latum

Procercoid

L3 of D. latum

Plurocercoid

Vitamin deficiency associated with D. latum

Vitamin B12 deficiency

Drug of choice for D. latum

Praziquantel

Sparganum mansoni

Disease: Sparganosis

Habitat of Sparganum mansoni

Skin, subcutaneous tissue, muscle

Infective stage of Sparganum mansoni

Procercoid/Plurocercoid larva

Diagnostic stage of Sparganum mansoni

Plurocercoid larva

Clinical manifestation of Sparganosis

Localized inflammation, cerebral and ocular sparganosis

Taenia saginata

Common name: Beef tapeworm

Disease caused by T. saginata

Taeniasis

Habitat of T. saginata

Duodenum

Intermediate host of T. saginata

Cow, cattle, carabao

Infective stage of T. saginata

Cysticercus bovis

Diagnostic stage of T. saginata

Eggs in stool, gravid segment

Mode of transmission of T. saginata

Ingestion of beef

Scolex of T. saginata

Unarmed scolex

Gravid segment of T. saginata

15–30 uterine branches

Taenia solium

Common name: Pork tapeworm

Disease caused by T. solium

Taeniasis, Cysticercosis

Habitat of T. solium

Small intestines

Intermediate host of T. solium

Pig

Infective stage of T. solium

Cysticercus cellulosae

Laboratory diagnosis of T. solium

Eggs and segments in stool; Scotch tape swab

Mode of transmission of T. solium

Ingestion

Scolex of T. solium

Armed scolex

Rostellum of T. solium

Double crown of hooks

Gravid segment of T. solium

7–15 uterine branches

Most common organ involved in cysticercosis

Brain (Neurocysticercosis)

Taenia egg

Contains hexacanth embryo

Hexacanth embryo

Contains 6 hooks

Diagnostic feature of Taenia egg

Radial striations

Hymenolepis nana

Common name: Dwarf tapeworm

Disease caused by H. nana

Hymenolepiasis

Habitat of H. nana

Upper ileum

Smallest tapeworm of man

Hymenolepis nana

Infective stage of H. nana

Embryonated ova, cysticercoid larva

Diagnostic stage of H. nana

Ova in stool

Intermediate host of H. nana

Fleas, flour beetles

Egg feature of H. nana

Bipolar thickening and bipolar filaments

Drug of choice for H. nana

Praziquantel

Hymenolepis diminuta

Common name: Rat tapeworm

Disease caused by H. diminuta

Hymenolepiasis

Habitat of H. diminuta

Small intestine

Infective stage of H. diminuta

Cysticercus larva

Intermediate host of H. diminuta

Rat flea, mouse flea, flour moth, flour beetle

Egg feature of H. diminuta

No bipolar filaments

Characteristic uterus of H. diminuta

Sac-shaped uterus

Dipylidium caninum

Common name: Double-pored tapeworm

Disease caused by D. caninum

Dipylidiasis

Habitat of D. caninum

Small intestines

Definitive host of D. caninum

Dog and cat

Accidental definitive host of D. caninum

Human

Intermediate host of D. caninum

Larval flea

Infective stage of D. caninum

Cysticercoid larva

Diagnostic form of D. caninum

Egg packets

Characteristic proglottid of D. caninum

Double genital pores

Characteristic eggs of D. caninum

Egg packets containing 5–15 eggs

Echinococcus granulosus

Common name: Hydatid worm