112.3 CESTODA (CESTODES)

What are CESTODA

Tapeworms

What is an tapeworm

segmented flatworms

What kind of host does cestoda aka tapeworms require

intermediate host

Where does the cestoda aka tapeworm live in the human body

intestines

What is the scolex

head of the worm that attaches to the intestine

neck of scolex produces proglottids

What is the proglottids

segments containing  male & female sex organs (monoecious) (hermaphroditic)

when mature, uterine branches filled with eggs

motile; break off & migrate out the anus

What is an Cysticercus larva

larval stage ingested by humans

contains invaginated scolex inside a protective membrane

What is an eggs

most contain a hexacanth embryo (oncosphere), with six hooklets

Taenia adult

What is the Hymenolepis nana

Dwarf tapeworm

How can a human acquire Hymenolepis nana

ingest egg with hexacanth embryo

Direct fecal-oral transmission(most common)

infected insect intermediate hosts

What is the diagnostic stage for Hymenolepis nana

eggs in stool

round to oval with a large space between embryo and shell

two polar thickenings give rise to  4-8 polar filaments

What does the Hymenolepis nana egg have that others do not

hexacanth embryo

What kind of disease manifestation do Hymenolepis nana have

abdominal pain, diarrhea

irritability and headache

peripheral blood eosinophilia

Hymenolepis nana

Hymenolepis nana

Diagnostic egg

What is Taenia solium

Pork tapeworm

What is the infected stage for Taenia solium

encysted cysticercus (larva) in pork muscle

How can a human acquire taenia solium

humans eat undercooked  pork

Where does the Taenia solium live in the human body

cysticercus  evaginates in human intestine and attaches to small intestine where it develops  into the adult worm 

How long is Taenia solium

up to 7 meters long

What does the scolex look like on Taenia solium

four suckers and hooked rostellum

How many proglottid does Taenia solium have

7-13 uterine branches

What is the disease manifestation for Taenia solium

vague abdominal pain, indigestion

loss of appetite

how many suckers does the tawnia solium have

4

Taenia solium (scolex)

Taenia solium (proglottid)

What is the Taenia saginata

Beef tapeworm

how can a human acquire Taenia saginata

humans eat undercooked beef

what is the infective stage for Taenia saginata

cysticercus larvae encysted in beef muscle

Where does Taenia saginata live in the human body

cysticercus evaginates in small intestine and scolex attaches to intestinal wall where it develops into the adult worm

How long is the Taenia saginata

10 meters long

What does the scolex look like on Taenia saginata

four suckers; no hooks on rostellum

How many branches does Taenia saginata have on it proglottid

15-20 uterine branches

What is the disease manifestation for Taenia saginata

vague abdominal pains; indigestion

loss of appetite

Taenia saginata           (scolex)

how many suckers does Taenia saginata  have

4

What is the diagnostic stage for Taenia saginata

eggs in stool

round with striated shell

hexacanth embryo (oncosphere) inside

What is Diphyllobothrium latum

Fish tapeworm; broad tapeworm

How is Diphyllobothrium latum Distribution

worldwide; in US-- Great Lakes

how can a human acquire Diphyllobothrium latum

ingest raw or pickled fish

What is the infective stage for Diphyllobothrium latum

plerocercoid larvae encysted  in fish (that ate an infected copepod

how long is Diphyllobothrium latum

10 meters long

What does the scolex look like on Diphyllobothrium latum

elongated with 2 sucking grooves--one dorsal; the other ventral

What does the proglottid look like on Diphyllobothrium latum

broad (wider than it is long ) with rosette uterine branches

What is the Disease manifestations for Diphyllobothrium latum

vague abdominal distress; nausea; vomiting

Vit. B 12 deficiency/ macrocytic anemia)

Diphyllobothrium latum (scolex)

Diphyllobothrium latum (proglottid)

What is the Diagnostic stage for Diphyllobothrium latum

eggs in stool

broadly oval

operculum at one end; small knob at the opposite (aboral) end

Diphyllobothrium latum ( Diagnostic Egg)

D. Latum eggs:  opercula open

Diphyllobothrium latum (broadfish tapeworm)

What are some Accidental tapeworm infections

Echinocoocus granulosus (dog tapeworm)

Cysticercosis of Taenia solium  (but rarely T. saginata)

Hymenolepis diminuta

Dipylidium caninum

Taenia egg

Taenia

D. latum

H. nana

What is Echinococcosis

Accidental ingestion of eggs from infected dog or sheep

What mainly the infection area for Echinococcosis

sheep raising areas

Where does the Echinococcosis Hexacanth embryo develops into

hydatid cyst

What human bodies parts do Echinococcosis attack

Liver, lungs or other tissues

Echinococcus granulosus (hydatid tapeworm)

What is Cysticercosis

is a potentially dangerous infection; results when human accidentally ingests the eggs of Taenia solium

Where is the hexacanth embryo in Cysticercosis released at

intestine & enters circulation

Where does the hexacanth embryo in cysticercosis develops and into

develops into cysticercus in any tissue/organ (striated muscle, eye and brain most often affected)

What are the features of Cysticercosis

called “bladder worm”--oval, translucent with invaginated scolex with 4 suckers and circle of hooklets on rostellum

What are the Disease manifestations of cysticercosis

striated muscle: pain, weakness & cramps

brain: neurosymptoms/convulsions

eyes:  intraorbital pain; retinal detachment; light flashes; blurred vision

What is Hymenolepis diminuta

Rat  tapeworm

How can humans acquire Hymenolepis diminuta

Humans acquire the worm by eating fleas with infective cysticercoid  

What is the Diagnostic stage for Hymenolepis diminuta

eggs (similar to H. nana) in stool

eggs  larger, and  do not have polar filaments

Hymenolepis diminuta Diagnostic Egg

Taenia

H. diminuta

H. nana

What is Dipylidium caninum

Dog tapeworm

How does children acquire Dipylidium caninum

eating fleas with D. caninum larvae

What is the Diagnostic stage for Dipylidium caninum

Egg packet (15-25 taenia-like eggs)  in stool

        Dipylidium caninum