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Tapeworm Infestation

Cestodes are generally flat, segmented and ribbon-like worms, and are commonly known as tapeworms. They have no

mouth or digestive system and so absorb nutrients across the body wall (cuticle).All members of this class are parasitic.

Characteristics of Cestodes (Tape worm)

A chain of reproductive units called strobilla with scole (hold fast organ) attached to the intestinal wall

!cole has suckers and rostellum. !cole is armed (with hooks) or unarmed (without hooks)

"o organs of prehension or digestion. "utrients absorbed through specialised integument (body wall # skin)

$lat shape affords maimum absorption of nutrients

Taenia saginata(human tapeworm% contain about &,''' segments and is around . metre long)* +chincoccus

granulosus ( ust about & to mmlength)

oth sees in the same individual

!ome segments have uterine pore for escape of eggs

Those without the pores, segments detach when they become mature ( gravid)

+ither eggs or the segments are found in the faeces ( starts appearing in faeces si

to eight weeks after ingestion of cysticercus

/e0uire intermediate hosts to complete lifecycle

1roduce eggs

2ststage larva called as oncosphere containing heacanth embryo

&ndstage larvae (cysticercoid) fluid filled bladder with one or more scolices (bladder worm)

The body is divided into the scolex, neck and

proglottids

o The scolex (head): The scole is usually modified

with hooks and#or suckers which fasten to the host gut

wall and provide an anchor to prevent removal of theworm by host bowel activity.

o The neck:The neck is an unsegmented region of highregenerative capacity. 3f treatment fails to eliminatethe neck and scole, the entire worm may regenerate.

o Proglottids (segments):The body is divided into

sections called proglottids. 1roglottids closest to the

neck are undifferentiated. As proglottids movecaudally, each develops hermaphroditic se organs.

4istal proglottids are gravid and contain eggs in auterus. The mature proglottids, gravid with eggs,

detach and are voided with the host feces.

Different segments of tapeworm

ife cycle

The life cycle is often comple and involves intermediate hosts. All cestodes cycle pass through stages5eggs, larvae,and adults. Adults inhabit the intestines of definitive hosts, mammalian carnivores. !everal of the adult tapeworms that

infect humans are named after their intermediate host%

The fish tapeworm (Diphyllobothrium latum),

The beef tapeworm (Taenia saginata), and

The pork tapeworm (Taenia solium).

+ggs are ecreted with faeces into the environment and ingested by an intermediate host (typically another species) in

which larvae develop, enter the circulation, and encyst in the musculature or other organs. 6hen the intermediate hostis eaten, cysts develop into adult tapeworms in the intestines of the definitive host, restarting the cycle. 6ith some

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cestode species (e.g., T. solium), the definitive host can also serve as an intermediate host and develop tissue cysts

instead of intestinal worms if eggs are ingested.

Life Cycle of Tapeworm

Pathogenicity

Although adult tapeworms do cause disease, it is the cystic forms in intermediate hosts that are of great overallveterinary and public health importance. These can cause severe and even lethal disease, most importantly in the brain,

but also in the liver, lungs, eyes, muscles, and subcutaneous tissues.3n humans, T. soliumcauses cysticercosis, andEchinococcus granulosusandE. multilocularis causehydatid disease.

Sparganum mansoniand T. multicepslarvae also can infect humans

Thus, some species live in the intestines of dogs and cause no detectable harm to them, but can grow into football-si7ed cysts in the liver and lungs of other hosts as humans who are unfortunate enough to ingest the eggs. 3ngestion of

cysts in meat and fish can also cause disease in humans, ranging from the benign to the life-threatening depending on

the tapeworm species involved.Adult tapeworms in the intestine have also been associated with intestinal upsets and anaemia in humans, and colic in

horses.

!ymptoms, !igns, and "iagnosis

Adult tapeworms are so well adapted to their hosts that they cause minimal symptoms. 8arvae, however, may elicit

intense immunologic reactions as they travel through tissues (hence inducing immunity) and cause severe disease when

they settle in etra-intestinal sites.Adult tapeworm infections are diagnosed by identifying eggs or gravid proglottid segments in stool. 8arval disease isbest identified by imaging studies, such as brain CT scan or 9/3 scan, and for some species, serologic tests.

Treatment and Prevention

The anthelmintic agents, pra7i0uantel and niclosamide, are effective for most intestinal tapeworm infections.1ra7i0uantel : 2 mg#kg 6 in horses

: .;< mg#kg in sheep

: < mg# kg in dogs and cats

"iclosamide :

!ome etra intestinal infections respond to anthelmintic treatment, whereas others re0uire surgical intervention.

Prevention and control

Thorough cooking (to temperature = C ?= 2 $@) of pork, beef, lamb, game meat, and fish*

/egular worming of dogs and cats*

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1reventing recycling through hosts, such as dogs eating dead carcasses reduction and avoidance of intermediate

hosts such as rodents, fleas, and grain beetles*

9eat inspection* and

!anitary treatment of human waste

1rolonged free7ing of meat is effective, pickling is variably effective, and smoking and drying are ineffective.

#amilies:

2. Taeniidae% Taenia solium(cysticercus) ,T.saginata, T.ovis, T.multiceps(coenurus), T.hydatigena,Echinococcusgranulosus(hydatid)

&. 4ipylididae%D.caninum

. Anoplocephalidae%Monieia e!pansa, M.benedenienus% 4iphylobothrium% !pecies -D.latum(infection in man from fish)

enus% !pirometra% !pecies B S.mansonoides(definitive host cats)

Taenia solium

This parasite has a cosmopolitan distribution, with estimates of approimately

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-using clean utensils to prevent cross-contamination during food processing

-inspection of beef#pork for cysticerci-$ree7ing at -2'>C for 2' days

Taenia multiceps, The Coen&r&s Tapeworm

The adult worm is found in dogs or wild canids.

The larva is a bladderworm with multiple scoleces, called a coenurus.The usual intermediate host is the sheep.

Treatment is chiefly surgical, although the drugs used for cysticercosis may also be effective against coenurusinfection

Echinococcus granulosus

+chinococcosis (hydatid disease) can develop in any tissue site, including the liver, lungs, heart, brain, kidneys, andlong bones.

The clinical manifestations depend on the site and si7e of the cyst, but resemble those of a slow-growing tumor thatcauses gradually increasing pressure.

Dipylidium caninum

3nfection of dogs and cats$leas are the intermediate hosts

Diphyllobothrium latum (The broad fish tapeworm)3nfection withDiphyllobothrium latumis usually asymptomatic, although occasional diarrhea, abdominal pain, fatigue,vomiting, di77iness, or numbness of fingers and toes may be present. +osinophilia develops during the early stages of

worm growth

Tapeworm of cattle and other r&minants

Moneia "Moneia e!pansa and M.benedini#

The adult tapeworms are about '' cm long with no rostellum and hooks. +ggs ofM.e!pansaare triangular-shapedwhile that ofM.benedinis0uare- shaped

"efinitive host: /uminants Intermediate host% Drbatid mites. The larva stage is called as cysticercoid.

Clinical signs

Eighly pathogenic in young animals, especially lambs !tunted growth

4ecreased weight gain

Anaemia

Dbstruction of small intestine

4iarrhoea

"iagnosis

$ecal sample eamination

Treatment

1ra7i0uantel : 2< mg#kg

Albenda7ole : 2' mg#kg

Prevention

Control mites in pasture by ploughing

'ther parasites of r&minants

$vitallina lahorea:4E% sheep and other ruminants (!mall intestine) 3E% 8ice

Stileia hepatica% 4E% /uminants (bile ducts)Thysamosoma actinoides% 4E% /uminants (ile ducts, small intestine, pancreatic duct)

3E% lice

Tapeworm of e&ines

$naplocephala perfoliata% 4E% e0uines (8arge and small intestines)$.magna% 4E% e0uines (stomach and small intestine)

I: Drbatid mites

Pathogenesis and clinical signs

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8arge number of parasites in intestine resuslts in weakness, cacheia, anaemia. Eeavy infestation can lead to death of

the animal.

Tapeworm of birds

Davainea proglottina% found in the duodenum of birds

They are armed with hammer-shaped hooks3E% 9olluscs

%allietina tetragona% found in the small intestine of birds. 3E% ants

%.echinobothrida% small intestine of chikens and turkeys 3E% antsCotugnia diagnophora% !mall intestine of birds

Amoebotaenia sphenoides% small intestine of fowls. /ose-thorn shaped hooks3E% earthworms

Pathogenesis of tapeworms in birds

%.echinobothridacauses nodule formation at the site of attachmentsevere enteritis

D.proglottinabury deep in the intestinal villihaemorrhage, necrosis and desesntry

Clinical signs /etarded growth in young and reduced production in adults

8oss of condition, emaciation, anaemia

1artial or complete paralysis

"iagnosis

ravid segments in feces, clinical signs and postmortem eamination

Treatment

"iclosamide : && mg#kg

Albenda7ole, Dybenda7ole and pra7i0uantel

Control

The control measures are directed at the control of intermediate hosts. 3nsecticides can be used for the control of

intermediate hosts.

/egular deworming of birds