Module 12 - Order Cyclophyllidea (True Tapeworms) II

❖ Family Dilepididae ➢ Amoebotaenia cuneata ❖ Family Dipylidiidae ➢ Choanotaenia infundibulum ➢ Dipylidium caninum ➢ Diplopylidium ➢ Metroliasthes lucida ❖ Family Hymenolepididae ➢ Zoonotic species ▪ Rodentolepis (=Hymenolepis, Vampyrolepis) nana ▪ Hymenolepis diminuta ➢ Zoophilic species ▪ Hymenolepis microstoma ▪ H. carioca ▪ H. lanceolata ▪ H. cantaniana ▪ Diorchis nyrocae ❖ Family Fimbriariidae ❖ Family Taeniidae ➢ Human taeniids ▪ Taenia saginata ▪ T. solium ▪ T. asiatica ➢ Taenids of carnivores ▪ Cysticerci-producing species • Taenia pisiformis • T. hydatigena • T. cervi • T. krabbei • T. hyaenae • T. ovis • T. crassiceps ▪ Coenuri-producing species • T. (=Multiceps) multiceps • T. (=Multiceps) skrjabini • T. serialis ▪ Strobilocercus-producing species • T. (=Hydatigena) taeniaformis ▪ Hydatid-producing species • Echinococcus granulosus • E. multilocularis • E. vogeli • E. oligarthus

Gravid uterus persists as transverse sac

Family Dilepididae

It occurs in the SI of fowl throughout the world, roughly triangular in shape

Amoebotaenia cuneata

IH of Amoebotaenia cuneata. What develops in it after 14 days

earthworms

• Eisenia

• Pheretina

• Ocnerodrilus

• Allobophora

cysticercoids

Prepatent period of Amoebotaenia cuneata

4 weeks

• Uterus is replaced by capsules containing 1 or more eggs

• Testes usually more than 12

Family Dipylididae

• It occurs in the upper half of the SI of the fowl and turkey, has 16-20 slender hooks, 1 set of genitalium.

• Genital pores are regularly alternating, leave the body before they become gravid

• eggs has distinct elongate filaments

Choanotaenia infundibulum

IH of Choanotaenia infundibulum

• housefly (Musca domestica)

• beetles (Geotrupes, Aphodius, Calathus, Tribolium)

Double-pored tapeworm of dogs and cats, creeping seed, flea tapeworm, cucumber tapeworm occurring in the small intestine, occasional in man.

Dipylidium caninum

most common tapeworm of dogs and cats up to 50 cm

Dipylidium caninum

Its scolex has rostellum with 3-4 rows of rose thorn-shaped hooks

Dipylidium caninum

Dipylidium caninum proglottids has how many sets of genitalia

2 sets of genitalia (ovary and vitelline gland form a mass on either side resembling a bunch of grape); mature and gravid ones have a characteristic elongate oval shape like a cucumber seed

eggs of Dipylidium caninum lie in egg capsules where each contains up to how many eggs

• 8-15 usually

• but up to 30 eggs

Gravid proglottids of this species detach and either wander out of the anus or passed out with the feces; egg capsules are released while the proglottids are crawling or after desiccation

Dipylidium caninum

cysticercoids of Dipylidium caninum develop as hyperparasites in its IH. Give its IH.

• fleas

  • Ctenocephalides canis

  • C. felis

  • Pulex irritans

• lice

  • Trichodectes canis

  • Heterodoxus longitarsus

In heavy infection of Dipylidium caninum, these signs and symptoms may occur.

• restlessness

• abdominal pain

• diarrhea

• unthriftiness

• dull coat

• excessive grooming of the perineum (scooting behavior) due to itching caused by active proglottids

Control of Dipylidium caninum

• IH control

• Praziquantel

T/F. Using fluralaner is also a form of treatment and control of Dipylidium caninum

TRUE (it can be used for fleas)

2 IH of Diplopylidium that are required

• beetle

• reptile or small animals

It is a rare parasite in the SI of the fowl and turkey in North America, India and Africa. Its scolex has no rostellum and hooks; 20 mm by 1.5 mm wide.

Metroliasthes lucida

IH of Metroliasthes lucida

grasshoppers

• Chorthippus

• Paroxya

• Melanoplus

It is a huge family consisting of numerous genera affecting birds and mammals which has unilateral genital pores, has 1-4 number of testes which is a large main morphological feature.

Family Hymenolepidae

Family Hymenolepidae has a rostellum which bear what structures?

single circle of hooks

IH of Family Hymenolepidae where its cysticercoids are produced

arthropods

Zoonotic species of Family Hymenolepidae

• Rodentolepis nana

• Hymenolepis diminuta

Rodentolepis nana is also known as (commo name)

Dwarf tapeworms of rats and mice

Its proglottids has 3 testes each. Eggs are oncospheres type with a thin, hyaline outer membrane and an inner thick membrane with polar thickenings and filaments that bear several filaments; released by apolysis

Rodentolepis nana

T/F. The life cycle of Rodentolepis nana has direct and indirect life cycle in which its direct cycle utilizes beetles (Tenebrio) as IH.

False, indirect if beetles.

T/F. Direct life cycle of Rodentolepis nana includes autoinfection in humans. Eggs hatch in the SI after ingestion and cysticercoids develop in the villi and then emerge into the lumen to mature.

TRUE

IH of Rodentolepis nana in indirect life cycle.

beetles

• Tenebrio sp.

Heavy infection of Rodentolepis nana may result into the ff:

• anorexia

• vomiting

• diarrhea

• pain in humans

• retarded growth or weight loss in rodents

Hymenolepis diminuta common name

rat tapeworm

It is larger than Hymenolepis nana but it lacks hooks on the rostellum.

Hymenolepis diminuta

It has 3 testes. Eggs are large with polar filaments.

Hymenolepis diminuta

Cysticercoids of Hymenolepis diminuta develop in its IH. What are these?

fleas and beetles particularly flour beetles - Tribolium spp.

Zoophilic species of Hymenolepididae (5)

• H. microstoma

• H. carioca

• H. cantaniana

• H. lanceolata

• Diorchis nyrocae

It is found in the gall bladder, bile ducts and duodenum of rodents

H. microstoma

It occurs in the SI of fowls, 8 cm in length.

Hymenolepis carioca

IH of Hymenolepis carioca (3)

• dung beetles

• flour beetles

• Stomoxys calcitrans

It occurs in the SI of chicken and other birds. 2 cm in length

Hymenolepis cantaniana

One of the most harmful hymenolepids

Hymenolepis lanceolata

IH of Hymenolepis lanceolata; large species - 13 cm

aquatic crustaceans

A common cestode of ducks which IH are ostracod or copepod crustacea

Diorchis nyrocae

It occurs in the SI of anseriform birds. The anterior portion forms a folded expansion or pseudocolex that is used for attaching host.

Fimbraria fasciolaris

IH of Fimbraria fasciolaris

copepods

• Diaptomus vulgaris

• Cyclops spp.

• This family contains the most medically important tapeworms of humans; also occurs in carnivores.

• Exceptionally large

• Has armed non-retractable rostellum (present on most species)

• Has numerous testes

• Ovary is found in the posterior margin of the proglottid

Family Taeniidae

Its eggs have a typical appearance (oval or spherical, thick embryophore riddled with numerous tiny pores that look like radial striations in optical section; contain a fully developed hexacanth embryo; the thin, hyaline outer membrane is often lost when the eggs are passed with the feces

Family Taeniidae

Life cycle and transmission of Family Taeniidae (5)

• Predator-prey relation

• Different types of metacestodes

• Sometimes known as bladderworms; they develop in mammals

• Some have specific names, which originally

• Some have specific names (originally served as scientific names)

Human taeniids (3)

• Taenia saginata

• Taenia solium

• Taenia asiatica

Has cuboidal scolex w/o rostellum

Taenia saginata

has spheroidal scolex with armed rostellum

Taenia solium

Has cuboidal scolex with unarmed rostellum

Taenia asiatica

• It has 14-32 uterine lateral branches of gravid proglottid and it leaves the host spontaneously.

• Vaginal sphincter are present

• Mature proglottid have bilobed ovary

Taenia saginata (also Taenia asiatica)

• It has 7-13 uterine lateral branches of gravid proglottid and it DO NOT leave the host spontaneously.

• Vaginal sphincters are ABSENT

• Mature proglottid have trilobed ovary

Taenia solium

Metacestode of Taenia saginata occurs in cattle and other species such as llama, goats, etc. (IH). It is called as?

Cysticercus bovis

Metacestode of Taenia solium occurs in pigs, black bears, other mammals, and humans (IH). It is called as?

Cysticercus cellulosae

IH of Taenia asiatica

pig, rarely in cattle

known as beef tapeworm of man

Taenia saginata

It is most common in humans, occurring nearly in all countries where beef is eaten. It lacks rostellum.

Taenia saginata

T/F. Mature proglottids of Taenia saginata are wider than long and the gravid ones are longer than wide.

TRUE

T/F. When Taenia saginata dries up, the midventral body ruptures where eggs escape.

TRUE

Duration of infective stage of Taenia saginata in its IH, cattle.

12 weeks.

what happens to the masseter and cardiac muscle of infected cattles of Taenia saginata

it appears to have the highest density

flesh infested by Cysticercus bovis (metacestode of Taenia saginata) is known as

measly beef

T/F. The juvenile scolex of Taenia saginata evaginates in response to bile salts, the bladder disappears and the budding of proglottids begins shedding of gravid proglottids occurs within 2-12 weeks

TRUE

Infestation of the pasture with eggs is due to indiscriminate defecation or the use of feces as fertilizer. Eggs survive in different environment and duration such as

eggs survive in:

• sewage - 16 days

• liquid manure - 71 days

• grass - 159 days

• Prevention of Taenia saginata.

• Required temp to kill the cysticerci

• cook beef until the beef in the middle is pink

• 56 degree C in cooking or -5 degree C for a week

Pathogenesis of Taenia saginata in man

• Usually asymptomatic or with mild to moderate symptoms of dizziness, abdominal pain, diarrhea, headache, localized sensitivity to touch, and nausea; delirium is rare but does occur

• Hunger pain is absent; there is loss of appetite

• Allergic reactions due to antigens released by the worms

• Psychological effects due to proglottids being passed out

• Proglottids may also migrate in other organs, e.g., bile ducts, appendix

Cysticerci in cattle begin to degenerate in ______ months after infection and large number of that may lead to death by ____ months

6 months; 9 months

this is a prominent feature of Taenia saginata

concomitant immunity

Drug of choice of Taenia saginata (2)

• Niclosamide

• Praziquantel

How to diagnose Taenia saginata (4)

• examining scolex or gravid segment

• ELISA for coproantigen

• meat inspection - 15-27% of mildly infected carcasses

• PCR-restriction fragment length polymorphism

Preventive measures of Taenia saginata (4)

• Sanitation

• Use sewage sludge fertilizer only for cultivated fields

• Condemnation of heavily infected carcasses

  • Mildly infected – freeze at -10˚C for 10 days or -18˚C for 3-4 days and then use for preparation of half-treated products

• Cooking of meat properly

Asian Taenia is also known as

Taenia asiatica

cysticerci of Taenia asiatica develop in the liver and other viscera of pigs for how many weeks? (have small hooks in their scolex)

4 weeks

armed or pork tapeworm of man

Taenia solium

Up to 10mm long, usually 2-3, most dangerous tapeworm of man

Taenia solium

Cysticercus cellulosae develop in its IH’s, pigs, muscle, and other organs for how long?

10 weeks

Aside from pigs, what animals serves as IH of Cysticercus cellulosae

black bears

In man, cysticercus cellulosae mature for how long? longevity?

weeks, 25 years

T/F. cysticercosis (T. solium) occurs in other animals (in dogs, rabies-like signs) and more importantly in humans (about 50,000 death a year) as a result of ingestion of eggs from one’s self, from others or autoinfection by reverse peristalsis

TRUE

Most common sites of Taenia solium

• subcutaneous tissue

• eye

• brain (neurocysticercosis)

T/F. Dying cysticerci of T. solium can elicit inflammatory response but not fatal to host.

False, fatal.

3 types of bladderworm of Taenia solium (13% of the patients have them all)

• cellulose cysticercus

• intermediate form

• racemose form

has an invaginated scolex with a fluid filled bladder of 0.5-1.5 cm in diameter

Cellulose cysticercus

bladderworm with a scolex

Intermediate form

a scolex is not evident and it is large, 20 cm in diameter and contains almost 60 ml of fluid

Racemose form

Taenia sp. that is used as a biological weapon against primitive people

Taenia solium - Cysticercus cellulosae

Diagnosis of Taenia solium (5)

• Fecal exam

• Meat inspection

• ELISA for coproantigens

• Brain imaging – computerized axial tomography, magnetic response imaging (MRI)

• Enzyme-linked immunoelectrotransfer (EITB) for serum antibodies

Drug of choice for Taenia solium

• mebendazole or praziquantel in pigs - avoid condemnation of carcass

  • also used in humans except if in the eye

• albendazole and praziquantel in humans

Taeniids of carnivores

• dogs, fox

• IH - rabbit in the abdominal cavity, liver

• may cause hepatitis cysticercosa

• Cysticercus pisiformis

Taenia pisiformis

Taeniids of carnivores

• dogs, fox

• IH - livestock in the abdominal cavity, liver

• Majority of the proglottids do not pass with the feces but leave the dog perennially → diagnosis by adhesive tape method

• Cysticercus tenuicollis

Taenia hydatigena

Taeniids of carnivores

• fox, dogs (sometimes)

• IH - deer, roe deer in muscle

• Cysticercus cervi

Taenia cervi (deer tapeworm)

Taeniids of carnivores

• canids

• IH - reindeer, moose in muscle

• Cysticercus tarandi

Taenia krabbei (reindeer tapeworm)

Taeniids of carnivores

• hyena

• IH - dromedary, sometimes cattle in muscle and liver

• Cysticercus dromedarii

Taenia hyaenae

Taeniids of carnivores

• dog, fox

• IH - sheep, goat in muscle

• Cysticercus ovis

Taenia ovis

Taeniids of carnivores

• fox, sometimes dog

• IH - small rodents, dog, cats, and man

• Cysticercus longiocollis

Taenia crassiceps

Coenuri-producing species

• dogs

• IH - sheep, cattle, man in brain and spinal cord

• causes vertigo-like symptoms called gid, staggers, or sturdy

• Coenurus cerebralis

Taenia multiceps

Coenuri-producing species

• dogs, fox

• IH - sheep in muscle and SC tissue

• Coenurus skrjabini

Taenia skrjabini

Coenuri-producing species

• dog

• IH - rabbits in connective tissue, man

• Coenurus serialis

Taenia serialis

Strobilocercus-producing species

• cats

• IH - small rodents in liver

• Strobilocercus fasciolaris

Taenia taeniaformis - feline tapeworm