Cestodes

method of infection for Taenia saginata

eating raw and under cooked beef, eggs not infective to humans

Taenia ova

Taenia Ova

Taenia saginata adult worm characteristics that differentiate it from other taenia species

• 15-30 primary uterine branches

• No rostellum or hooklets on four suckers

Taenia saginata adult

Taenia solium method for infection

• hog is an intermediate host

• eating raw or undercooked pork

• ingesting the eggs

What body part is commonly involved with T. solium infection?

The brain.

T. solium adult worm

How does the Taenia solium differ from other tinae species

• 4 suckers with a rostellum with hooks

• proglottid with 7-15 uterine branches

Hymenolepis nana method of infection

ingestion of eggs and cysticercoid (arthropod)

H. nana Ova

prostoglodid are wider than long

H. nana adult worm

Hymenolepis diminuta method of infection

ingestion of cysticercoid larvae from arthropods

notice no filaments

Hymenolepis diminuta Ova

What size is H. diminuta

70-85um

Hymenolepis diminuta adult worm

The prostoglottid of H. diminuta are

wider than long

Diphyllobothrium latum method of infection

ingestion of raw or undercooked fish

What can Diphyllobothrium latum occassionally cause

Vit B12 deficiency

Diphyllobothrium latum Ova

Diphyllobothrium latum OVa have a

knob like projection and are opperculated

notice the rosette shaped uterus

Diphyllobothrium latum adult

Didylidium caninum method of infection

ingestion of infected fleas

egg packets for Didylidium caninum

egg packets for Didylidium caninum

Didylidium caninum scolex and proglottid

Each part that breaks off of Didylidium caninum is a

egg packet

What parasite causes Hydatid liver

Echinococcus granulosus

What parasite is associated with sheep and dogs

Echinococcus granulosus

Rupture of Echinococcus granulosus cysts cause

anaphylactic shock

Echinococcus granulosus is diagnosed with

Examination fo cysts, EIA, serological techniques

Hydatid Sand from Echinococcus granulosus

he cestode for which the gravid proglottid contains greater than 15 lateral uterine branches is

Taenia saginata

the disgnosis of Strogyloides stercoralis is usually made by detecting which form in stool specimens

The rhabditiform larvae

The scolex of taenia solium may best be differentiated from Taenia saginata by the presence of

An armed rostellum

The infective for of taenia saginata for humans is the

cyticercus

What organisms are most likely to be transmitted in the lab

• Ascaris lumbricoides

• Strongyloides

• hook worms

Stool specimens should be examine as soon as possible after passage. IF unpreserved specimens are allowed to sit overnight, all of the following may occur except:

A. rhabditiform larvae of Necator americanus may be present

B. eggs of ascaris may hatch

C. Troph of entamoeba histolytica will die

D. eggs of enterobius vermicularis may hatch

B.

A nemotode that is capable of causing rectal prolapse in heavy infection particularly in children is

Trichuris trichiura

teh mode of transmission for many parasites is fecal oral. The ability to infect the host via penetration through the skin is most commonly seen with

Ancylostoma duodenale filariform larvae