Cestodes ( Laboratory)

Platyhelminths or Flatworms

Dorsoventrally flattened with bilateral symmetry

• Segmented

• Ribbon-like appearance

• Do not have digestive tract And a circulatory system

Cestodes characteristics

Tegument

Cestodes obtain nutrients and excrete waste products through their outer surface called?

Hooks and suckers

Have highly specialized organs of attachment called?

• Egg

• One or more larval stages

• Adult worm

Three morphologic forms that exists in the typical cestode life cycle

• Scolex

• Neck region

• Strobila

3 distinct features common to all adult tapeworm

Oncosphere

Other name for hexacanth embryo m

Hexacanth embryo

Typical egg of cestodes = 6 hooks/ 3 pairs of hooks

Scolex

Head of the organism

Neck region

Region of growth ; segmentation/strobilization happens

Strobila

Series of proglottids

Gravid proglottids

Contains the egg of the organism

Mature proglottids

Contains both male and female (self-fertilization)

Pseudophyllidea and Cyclophyllidea

Order

Spatulate scolex with sucking grooves called Brothia

Scolex of Pseudophyllidea

Globular with four muscular suckers called Acetabula

Scolex of Cyclophyllidea

Have genital pores and uterine pore

Segments/ Proglottids of Pseudophyllidea

Have genital pores

Segments/ Proglottids of Cyclophyllidea

Apolysis

How are eggs released in Cyclophyllidea

Operculated, Immature,

require aquatic development of the embryo (Coracidium)

Eggs of Pseudophyllidea

Non-operculated, contains hexacanth embyro (6 hooks)

Eggs of Cyclophyllidea

Require two intermediate hosts

Intermediate hosts for Pseudophyllidea

Require one intermediate host

Intermediate hosts for Cyclophyllidea

• Taenia saginata

• Taenia solium

• Taenia asiatica / Taenia saginata asiatica

• Hymenolepis nana

• Hymenolepis diminuta

• Dipylidium caninum

• Raillientina garrasoni

• Dibothriocephalus latus

Enumerate Intestinal Cestodes

Embryophore

The embryo of The Taenia spp. is surrounded by a brown/yellow-brown shell known as an?

4

How many suckers does Taenia spp. have?

Has cushion-like rostellum with a double crown (row) of well-defined hooks

describe the scolex of Taenia solium

15 to 20

T. saginata uterine branches

7-13

T. solium uterine branches

Beef tapeworm

Common name fore Taenia saginata

Taeniasis

T.saginata disease

Upper jejunum ; can live up 25 years

T. Saginata adult worm habitat and life span of

1000 to 4000

Taenia saginata adult worm number of proglottids

devoid of hooks or a rostellum

describe the scolex of Taenia saginata

Taenia saginata

Irritated by alcohol

Humans

Definitive host of T. saginata

Cysticercus bovis

Infective stage of definitive host (T. saginata)

Cattle, cows

Intermediate host ( T. saginata)

Egg

Infective stage of Intermediate host (T. saginata)

Ingestion of raw or undercooked beef contaminated with cysticercus larva

T. saginata mode of transmission

Pork tapeworm

Taenia solium common name

Taeniasis, Cysticercus

T.solium disease

Upper small intestine

T. solium adult worm habitat

8,000 to 10,000

T. solium adult worm number of Ova in proglottids

Hogs, pigs, Humans

Intermediate host (T. solium)

Cysticercus cellulosae

Infective stage of Intermediate host ( T. solium)

Cysticercus bovis

ovoidal , milky white, about 10mm in diameter, and has a single scolex invaginated into a fluid filled bladder

Cysticercus cellulosae

Oval, translucent, and has an opaque invaginated scolex with four suckers and a circlet of hooks

Humans

Definitive host (T. solium)

Ingestion of raw or undercooked pork contaminated with cysticercus cellulosae

Mode of transmission ( T. soloum) Taeniasis

Fecal-oral route by ingestion of Taenia solium eggs from contaminated food or drink

Mode of transmission ( T. soloum) Cysticercosis

Striated muscle and in the brain

Where is Cysticercus commonly located?

Neurocysticercus

One of the most serious manifestations and considered as one of the most serious zoonotic diseases worldwide

T. saginata immature and mature proglottids

Square in shape, contain mature male and female reproductive organs.

2 large lobes

How many lobes of ovaries does T. saginata (mature, immature ) proglottids have?

Median club-shaped

Describe the uterus of the T. saginata found in the proglottids

300-400

T.saginata immature & immature Follicular testes

T. saginata Gravid proglottids

Typically rectangular, averaging 16-20 mm by 5-7 mm

• Undergo Apolysis

100-200

T. solium follicular testes

97,000 to 124,000

T. saginata number of ova in proglottids

30,000 to 50,000

T. solium, gravid proglottid number of ova

• Exercise proper sanitation practices

• Thorough cooking of meat (beef) prior to consumption is a primary measure

• Freezing at -20 degree celsius for 1 days kills the cysticerci

• Sanitary inspection of all slaughtered pigs, cows, and cattle should be done

• Meat inspection should include examination of the liver as well

• Promptly treating infected persons

Prevention and Control for Taenia spp.

• Stool

• Cellulose tape perianal swab

• India ink injection

• FECT

Taeniasis laboratory diagnosis

Stool

Specimen of choice for the recovery of Taenia spp. eggs, gravid proglottids, and scolex.

Cellulose tape perianal swab

High recovery rate of Taenia eggs

FECT

Useful im increasing the chance of demonstrating the eggs of Taenia spp.

Praziquantel

• 5-10 mg/kg , single dose

Drug of choice and dose for Taenia spp.

Albendazole

Alternative treatment /drug for Taenia spp.

• CSF analysis

• Computed axial tomography scans

• Nuclear magnetic resonance imaging

Diagnosis for Cysticercosis

• ELISA

• electro-immuno transfer blot

• Western blot for soecific IgG and IgM anticysticercal antibodies

• Dot-ELISA test

Taenia spp. Serologic tests

Asian tapeworm

Taenia asiatica /Taenia saginata asiatica common name

Taiwan, korea, Thailand, and Indonesia

Countries reported for Asian tapeworm

Liver of variable intermediate host ( Cysticercus viscerotropica)

Where is Cysticercus larvae found in T. asiatica?

Pigs, Cattle, Goats, Wild boars, and Monkeys

Intermediate host of T. asiatica

Consumption of raw pig liver

T. asiatica Mode of transmission

300-1000

Adult T. asiatica number of segments

Devoid of hooklets but with a prominent rostellum

Decribe scolex of T. asiatica

11-32

T. asiatica Gravid segment, lateral branches

Carry a vaginal sphincter

Describe T. asiatica Mature proglottids

Dwarf tapeworm

Hymenolepis nana common name

Hymenolepis nana

Smallest tapeworm infecting humans.

Found worldwide, mainly among children

Ileum

Hymenolepis nana adult worm habitat

Does not require bit in some cases :

• Rice and Flour beetles ( Tenebrio spp.)

Hymenolepis nana intermediate host

Humans

Hymenolepis nana definitive host

Hosts ingests eggs

Hymenolepis nana Mode of transmission (Direct)

Accidental ingestion of infected arthropods IH, and water, or food contaminated with the larvae

Hymenolepis nana Mode of transmission (indirect)

Hymenolepis nana , Ova/Egg

• Spherical or subspherical

• Colorless or clay-colored Embryophore

• Hexacanth embryo centrally located

• 3 pairs of hooklets

• Thin outer membrane ; Thick inner membrane wit conspicuous bipolar thickenings

• 4-8 hair-like polar filaments

Hymenolepis nana, scolex

• Sub-globular with four cup-shaped suckers.

• Short retractabke rostellum armed with a single row of 20 -30 Y-shaped hooklets.

• Neck is long and slender

Hymenolepis nana mature proglottids

contain 3 ovoid testes and 1 ovary

Hymenolepis nana gravid proglottids

Testes and ovary disappear while the uterus hollows out and becomes filled with eggs.

• consists of a sac-like uterus filled with eggs.

Stool

Hymenolepis nana specimen

Praziquantel (25 mg/kg, single dose)

Hymenolepis nana Drug of choice and dose

Nitazoxanide or Niclosamide

H. nana alternative drugs

• Proper Personal Hygiene

• Proper or appropriate environmental sanitation practices

• Infected cases should be thoroughly treated

• Fold must be properly stored and protected from possible infestation with grain beetles.

H. nana Prevention and control

Rat tapeworm

Hymenolepis diminuta common name

Hymenolepiasis

Hymenolepis diminuta disease

Rats, Humans (accidental)

Hymenolepis diminuta Definitive host

Flease, Beetles, Earwigs, Cockroaches , and Mealworms

Hymenolepis diminuta intermediate host

Ingestion of infected insects by rats or, accidentally by man

Hymenolepis diminuta Mode of Transmission

• Hexacanth embryo contains 3 pairs of hooks

• Thin inner membrane

• Exhibits bipolar thickenings but lacks the polar filaments

• Striated outer membrane

• Hooklets ( fan-like arrangement)

• Embryophore (colorless)

Hymenolepis diminuta Ova/Egg (describe)