S4 L4 Cestodes

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c YY

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Intestinal cestodes x ¦ saginata x ¦ solium x Ô nana x Ô diminuta x M caninum x M latum Extraintestinal Cestodes x Echinococcus sp x gpirometra

6 Gnown as the beef tapeworm 6 Ôumans serve ONLY as definitive host

p_{NO¦ as intermediate host}

p_{Ôuman cysticercosis MOEg NO¦ occur}

Adult worm

ÿInhabits upper jejunum ÿ-ay live up to 25 years

ÿ-easure 4 ± 10 m in length (25m); 1,000-4,000 proglottids

gCOLEX

 cuboidal scolex  1-2 mm in diameter  4 acetabula

 Mevoid of hooks or rostellum PROGLO¦¦IMg

-A¦RE GRAVIM

contain mature male and female

reproductive organs 2 large ovaries and a median

clubbeduterus

Follicular testes 300-400 Vagina has a sphincter

Proglottids are longer than they are wide

terus is distended with ova and has 15 to 20 lateral branches

Genital pores of proglottids are irregularly shaped

OVA

gpherical or subspherical in shape

in color, with a thick embryophore which appears striated because of numerous pits

Inside the eggshell is the oncosphere or embryo 30-45 um in diameter

Brownish provided with 3 pair of hooklets

Gravid proglottids undergo apolysis ù passed out/crawls out ù eggs are released

Cysticercus bovis: infective stage; ovoidal, milky white, 10mm diameter, single scolex invaginated into a fluid-filled bladder

Only 1 adult tapeworm is present in ¦ saginata infections

6 Gnown as the pork tapeworm of man

6 -an serve as both a definitive host and an intermediate host 6 Both intestinal and tissue infections occur in man

6 Adult worm inhabits the upper small intestines 6 ghorter than ¦ saginata, less number of proglottids 6 Adults measure 2-4 m in length; 800 ± 1000 proglottids

gCOLEX

acetabula; smaller; more spherical

Cushion-like rostellum with a double crown of 25-30 large and small hooks

PROGLO¦¦IMg

-A¦RE GRAVIM

presence of accessory ovarian lobe

absence of vaginal sphincter smaller number of follicular

testes (100 to 200)

Contains 7-15 uterine lateral branches

Also undergo apolysis but not very motile

EGGg

6 Indistinguishable from ¦ saginata

¦AENIA gOLI-

¦AENIA gAGINA¦A

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(2)

c DY

Misease caused:

6 Ingestion of eggs ùCYg¦ICERCOgIg 6 Ingestion of cysticercus ù¦AENIAgIg ¦AENIAgIg gY-P¦O-g:

Cysticercosis

Neurocysticercosis C¦ gcan findings:

1 Round low-density area without surrounding enhancement after administration of contrast dye (viable larva without inflammation) 2 Ring-like enhancement after

injection of contrast dye (dead larva)

3 gmall calcified area within a cystic space (dead scolex) MIAGNOgIg

¦AENIAgIg CYg¦ICERCOgIg

symptoms

history of eating undercooked beef or pork

recovery of proglottids and/or eggs in the stool

CNg and/or symptoms involving other organs history of ingesting food with

¦ solium eggs

radiographic localization of cysticercal lesions in tissues

¦REA¦-EN¦ ¦aeniasis

6 Praziquantel : 5-10 mg per kg as single dose for both adults and children

6 gcolex expulsion is essential 6 Criteria for cure :

ÿ Recovery of the scolex

ÿ A negative stool examination 3 months after treatment Cysticercosis

Neurocysticercosis:

Praziquantel : 50-75 mg/kg divided into 3 doses for 30 days or

Albendazole : 400 mg 2xday for 8-30 days gteroids

gurgical removal Ocular cysticercosis:

gurgical removal EPIME-IOLOGY

Related to the habit of eating raw or improperly cooked meat ¦ solium: glavic countries, Latin America, gouteast Asia,

China and India

¦ saginata: Etiopia and East Africa, Japan, gEA, Europe, Australia, Canada, g

Philippines: Prevalence of taeniasis: 0 56%; Northern Luzon ¦aeniasis prevention:

6 Adequate cooking of meat 6 Freezing meat below 10º C

Common Name: dwarf tapeworm

Misease: Ôymenolepiasis nana, dwarf tapeworm infection Geographic Mistribution

1 primarily limited in human beings to children in warm climates

2 prevalent throughout India, parts of the ggR, countries bordering the -editerranean, all countries of Latin America, Ôawaii and some of the islands of gouth and gouthwest Pacific

3 Common tapeworm in southeastern nited gtates -ORPÔOLOGY

Length: 25-40 mm No of Proglottids: 200 gCOLEX

6 small and globular

6 bears a short retractile rostellum with a single ring of 20-30 minute hooklet 6 provided with four cup shaped suckers

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NECG

6 long and slender

PROGLO¦¦IMg

I--A¦RE -A¦RE GRAVIM

ndifferentiated trapezoidal about 4x

as broad as long has a single genital

pore on its left side towards the anterior border

has three round testes and a bilobed ovary Contains the sacculate uterus filled with eggs OVA

6 grayish hyaline, nearly spherical 6 20-40 um in diameter

6 two thin membranous shells

6 inner membrane with two polar thickenings each provided with 4-8 threadlike filaments extending into the space between the two shells

6 hexacanth embryo with six hooklets enclosed by two membranes

EPIME-IOLOGY Ôuman strain

6 Only human tapeworm that does not require an intermediate host to complete its life cycle

6 -an is the natural final host

6 Infective stage is the embryonated ova transmitted toman through the agency of foods and drinks particularly raw leafy vegetables usually eaten as raw salad

6 It is more common in children and in institutionalized group 6 Ôumanity is the chief source of infection

-urine strain , Ôymenolepis nana var fraterna 6 Final hosts are rats and mice

6 -an is an accidental final host

6 Intermediate hosts are fleas and beetles

6 Infection of definitive host results from the ingestion of intermediate hosts harboring the cysticercoid larva -OMEg OF ¦RANg-IggION

ÿ Mirect hand to mouth

ÿ Less frequently, by contaminated food or water ÿ Possibly, by indirect intermediate hosts gY-P¦O-A¦OLOGY

1 Infection with a few Ôymenolepis nana may produce no symptoms 2 It my be responsible for:

a diarrhea b anorexia

c vomiting d insomnia

e loss of appetite and weight f iriirtability

g pruritus of the anus and nose h urticaria

I Choreiform symptoms

3 Ôeavy infection is invariably pathogenic a moderate to profuse diarrheic stools b abdominal pain

c anorexia and exaggerated disorders d extreme apathy

e epileptiform seizures LABORA¦ORY MIAGNOgIg

1 Recovery of the characteristic ova in the stools

2 Light cases with the aid of acid ether concentration technique ¦REA¦-EN¦

1 Praziquantel ± 25 mg/kg in single dose 2 Niclosamide ± 2 g each day, for 5-7 days children ± half of the adult dose

3 Paromomycin ± 45 mg/kg daily, given in four doses at hour intervals for a period of 5 days

PREVEN¦ION 1 Ôuman strain

a avoid ingestion of eggs by not eating raw vegetable salads b personal hygiene

c cleanliness of toilet seats 2 -urine strain

a Eradicate the rats and mice around the house b Residual spraying of their nests and burrows with insecticides

c Protection of cooked foods from arthropods

Common Name: rat tapeworm Misease: rat tapeworm infection Geographic Mistribution

1 cosmopolitan parasite of rats, mice and other rodents 2 has been reported from human hosts usually from children in

India, Indonesia, ggR, Japan, Philippines, gouthern Europe, Latin America from Argentina to -exico and Cuba and from several parts of the nited gtates

-ORPÔOLOGY

Length 10 to 60 cm by 3 to 5 mm No of proglottids 800-1000

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gCOLEX

6 Gnoblike; club-shaped

6 Provided with a rudimentary apical unarmed rostellum or a deep apical suctorial pocket without rostral hooklets 6 Provided with four relatively small cup shaped suckers NECG

6 ghort and stout

PROGLO¦¦IMg

ndifferentiated 0 8 by 2 5 mm

same as

Ôymenolepis nana only the segments are larger sacculate uterus filled with egg masses OVA

6 hyaline with straw colored hue 6 broadly ovoidal or subspherical 6 58 by 86 um

6 two egg membranes, outer and inner

6 inner membrane with two polar thickenings but with the absence of filaments

6 considerable space between outer and inner 6 hexacanth embryo enclosed by two membranes

EPIME-IOLOGY

6 -an is only an accidental final host

6 Rats and other murines are the natural final hosts 6 Principal intermediate hosts are the larval rat, mouse fleas

and adult mealworm beetle

6 Other intermediate hosts ± fleas, myriapods, cockroaches, beetles, lepidopterans

6 Infective stage to the final host is the cysticercoid larva in the arthropod host

6 Ôumans are infected accidentally by food or hands contaminated with infected insects

gY-P¦O-A¦OLOGY

6 Ôymenolepis diminuta usually produces no symptoms 6 Indigestion and abdominal pain are the presenting

complaints in infants LABORA¦ORY MIAGNOgIg

6 Recovery of the characteristic ova in the stools ¦REA¦-EN¦

6 game as Ôymenolepis nana PREVEN¦ION

6 Eradicate the rats and mice around the house 6 Residual spraying of their nests and burrows with

insecticides

6 Protection of cooked foods from arthropods

Common name: double pored dog tapeworm Misease: Mipylidiasis, dog tapeworm infection Geographic Mistribution

1 A common tapeworm of the dogs and cats throughout the world; also reported from wild cats and foxes

2 Ôuman infection rare but reported from European countries, the nited gtates, Argentina, Rhodesia, China and the Philippines

3 In the Philippines, survey of dogs ± prevalence of 5 19% to 36%; dog and cat fleas ± 2 4%

-ORPÔOLOGY

1 pale reddish adult worm measuring 15 to 70 cm In length 2 strobila ± a chain of melon shaped proglottids 3 No of proglottids ± 60 to 175

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gCOLEX

6 rhomboidal

6 retractile conical rostellum armed with 30 to 150 rose thorn shaped hooklets arranged in transverse rows

6 four prominent oval suckers NECG

6 ghort and slender

PROGLO¦¦IMg

Broader than long when very young gquare as they become older vase shaped, melon seed shaped or pumpkin seed shaped double sets of reproductive organs genital atrium on each side of the segment

Vase shaped, melon seed-shaped or pumpkin seed shaped filled with polygonal

shaped uterine egg pockets or egg capsule containing 8 to 15 eggs

OVA

6 gpherical

6 thick albuminous covering

6 hexacanth embryo with three pairs of lancet shaped hooklets

EPIME-IOLOGY

1 Mefinitive hosts are dogs and cats and wild carnivora 2 -an especially children are only accidental final hosts 3 Intermediate hosts are larval fleas of the dog, cat and human being and the dog louse

Mog flea ± Ctenocephalides canis Cat flea ± Ctenocephalides felis Ôuman flea ± Pulex irritans dog louse ± ¦richodectes canis

4 Ingestion of the infected fleas cause infection of the final host 5 Infants and young children are usually infected because of their close contact with their pet cats

gY-P¦O-A¦OLOGY

Y Light infections ± asymptomatic D -ay cause:

a slight intestinal discomfort b epigastric pain

c diarrhea d anal pruritus e allergic reactions MIAGNOgIg

1 Clinical - difficult since symptoms are nonspecific 2 Laboratory

a based upon the demonstration of:

1 A single or chain of melon shaped 2 proglottids

3 Egg pockets or egg capsules 4 Embryonated ova

5 Ripe or gravid proglottid ¦REA¦-EN¦

1 Praziquantel ± 10 mg per kg in a single dose

2 Niclosamide ± 4 tablets(2 g) chewed thoroughly in a single dose after a light meal

3 Paromomycin ± 1 g every 4 hours for 4 doses 4 uinacrine hydrochloride- 0 8 g given over a half hour

interval PREVEN¦ION

1 Periodic deworming of pet cats and dogs is recommended 2 Insecticide dusting of dogs and cats are effective against

fleas

3 ¦he potential danger of playing with pets must be included in the health education of children

4 gmall children should not be allowed to fondle dogs and cats infected with fleas and lice

Common Name: broad or fish tapeworm

Misease: Miphyllobothriasis; fish tapeworm infection; broad tapeworm infection

Geographic Mistribution

1 prevalent in regions of the temperate zones where freshwater fish form an integral part of the diet

2 common in Northern Europe, Russia, North America, -anchuria and Japan and gouth America

3 has been reported in man once from the Philippines -ORPÔOLOGY

Ivory or grayish yellow Length ± 3 to 10 meters No of proglottids ± 3000 gCOLEX

6 spatulate, almond shaped 6 2-3 mm by 1 mm

6 no rostellum nor hooklets 6 two deep dorsoventral

suctorial grooves called bothria NECG

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c |Y

6 unsegmented, several times the length of the scolex

-A¦RE PROGLO¦¦IM 6 broader than long

6 contains both male and female reproductive organs

6 characteristic morphologic feature ± dark rosette-like coiled uterus at the center

RIPE OR GRAVIM PROGLO¦¦IM 6 game as mature proglottid

OVA

6 yellowish brown in color 6 measures 55-76 u by 41-56 um 6 inconspicuous operculum at

one end

6 small knoblike thickening at the other end

6 contains plenty of yolk cells 6 immature when oviposited

EPIME-IOLOGY

6 ¦he final hosts are man and other piscivorous mammals such as dog, cat, leopard, foxes, mink, pig and bears 6 First intermediate hosts ± copepods of the Genus Miaptomus

and Genus Cyclops

6 gecond intermediate hosts ± fresh water fish like pike, trout, salmon,whitefish, turbot and carp in the Philippines 6 Infective stage to man and other final hosts ± plerocercoid

larva in the 2nd_{intermediate host}

6 sual vehicle for transmission- raw, partially cooked or frozen fish eaten raw

PA¦ÔOGENEgIg ANM gY-P¦O-A¦OLOGY 1 Mue to adult worm

a systemic toxemia due to by products of thea dult worm absorbed into the host¶s tissue

b mechanical obstruction due to large numbers of worms when they become entangled together c bothriocephalus anemia or tapeworm

pernicious anemia (Miphyllobothrium latum competes with the host for the available supply of Vitamin B12)

Miagnosis 1 Clinical

a tapeworm appetite, abdominal pain and anemia particularly in people living in endemic areas 2 Laboratory

a demonstration of the characteristic egg in the stool using acid ether concentration technique

¦REA¦-EN¦

1 Niclosamide ± 4 tablets (2 g) chewed thoroughly in a single dose after a light meal

2 Paromomycin ± 1 g every 4 hours for 4 doses 3 Praziquantel ± 10 mg per kg in a single dose

4 uinacrine hydrochloride ± 0 8 g given over a half hour interval

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c ]Y

PREVEN¦ION

1 thorough cooking of all fresh water fish used for human consumption

2 freezing of fish for 48 hours at a temperature of ± 10 C 3 tasting of raw fresh water fish while being prepared for

the table should not be practiced 4 proper treatment and disposal of sewage

NONBRANCÔING gPARGANA

gpargana or plerocercoid larva of several species of

gpirometra(Miphyllobothrium) mansonoides ± found also in Ôumans Geographic Mistribution

1 Found in East and goutheast Asia, Japan, Indochina and to a lesser extent North and gouth America

-ORPÔOLOGY

6 Elongated, ivory white ribbonlike larvae 6 Ôas an anteroposterior polarity 6 Pseudosucker

6 Elongated like a small tapeworm 6 No scolex and no defined proglottids LIFE CYCLE ± similar to Miphyllobothrium latum EPIME-IOLOGY

1 ¦he final hosts are dogs and cats

2 ¦he first intermediate hosts are the copepods of the Genus Cyclops

3 ¦he second intermediate hosts are the frogs, lizards, snakes, bird and monkey

4 -an is an accidental intermediate host 5 ¦he infective stages are:

procercoid larva in the Cyclops

 plerocercoid larva (spargana) in the tissues of 6 cold blooded vertebrates

7 Ôuman infection results from:

ingestion of Cyclops infected with procercoid larva  ingestion of raw flesh of cold blooded animals

harboring the plerocercoid larva

1 Found in any part of the body especially a Eyes

b gubcutaneous and muscular tissues of the thorax c Abdomen

d thighs e inguinal region f thoracic vertebra

2 Elongating and contracting larvae within a slimy matrix cause an inflammatory and painful edema of the surrounding tissue

3 Megenerated larvae cause intense local inflammation and necrosis but no fibrous tissue formation

4 Infected persons may show: a local indurations b periodic giant urticaria c edema

d erythema accompanied by chills, fever and high eosinophilia

e ocular infection ± painful edematous conjunctivitis with lacrimation and ptosis

MIAGNOgIg

6 By finding the larvae in the lesion ¦REA¦-EN¦

6 gurgical removal of the larval plerocercoid PREVEN¦ION

1 Only potable water should be drank

2 Raw water from streams should be avoided as this may contain infected Cyclops

3 se of cold blooded vertebrates as poultices should be avoided

4 Cold blooded vertebrates when eaten should be in a cooked state

BRANCÔING gPARGANA

Budding larval tapeworm ± gpirometra proliferum Geographic Mistribution:

1 Reported in Japan and nited gtates -ORPÔOLOGY

1 Larva ± irregular, lateral, supernumerary processes that may bud off as new spargan in the tissues

LIFE CYCLE ± unknown

MIAGNOgIg: finding the larvae in the chylous nodular lesions

Misease caused by the larval stage which is acquired when eggs are ingested

Echinococcus granulosus : causes hydatid cysts Echinococcus multilocularis : alveolar echinococcosis Mogs and other canines are the most common definitive

hosts

Echinococcus granulosis (ÔYMA¦IM) Geographic distribution

-ORPÔOLOGY Adult worm: 6 3-6 mm length

6 possess pyriform scolex,short neck and 3 proglottids (immature, mature and gravid)

Ôydatid cyst : usually measures 1-7 cm in diameter; consists of protoscolices the cysts (2 to 30 cm) are constituted by an external acellular cuticule and an inner cellular "germinal" layer (10-25 µ) that produces the brood capsules containing 6-12 protoscolices or single protoscolices (Germinal layer with a protoscolex)

ECÔINOCOCCg

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c Y

"Ôydatid sand" : free protoscolices in the cyst

Fluid aspirated from a hydatid cyst will shows multiple protoscolices (size approximately 100 µm), each of which has typical hooklet ¦he protoscolices are normally invaginated (left), and evaginate (middle, then right) when put in saline

LIFE CYCLE

6 Pathology caused by developing larval cyst in the intermediate host

6 LIVER : most common and most important site of involvement (70%); 85% located in the right lobe gY-P¦O-g

MIAGNOgIg

Endemicity gymptoms X-ray and C¦ scan gerology gkin (Casoni) test gEROLOGY

Indirect hemagglutination (IÔA), indirect fluorescent antibody (IFA) tests, and enzyme immunoassays (EIA) are sensitive tests for detecting antibodies in serum of patients with cystic disease;

sensitivity rates vary from 60 to 90% positive reaction is confirmed by immunoblot assay or any gel diffusion assay that demonstrates the echinococcal "Arc 5"

Casoni test (an immediate hypersensitivity skin test used to detect sensitization to hydatid antigen)

¦REA¦-EN¦ ANM CON¦ROL gurgical removal of the cyst Praziquantel

Avoidance or treatment of infected canine

For inoperable cysts ± PAIR ( puncture, aspiration, injection, reaspiration)

Echinococcus multilocularis

Foxes are the natural definitive host gmall rodents are the intermediate hosts

Ôumans infected by eating raw plants contaminated with feces of infected canines or cats

Cyst wall: not clearly delineated form surrounding tissue; porous, spongy mass of small irregular cavities with a jelly like matrix

gimilar to E granulosus, except:

¦hat secondary hosts and reservoir are rodents ¦he egg produce multilocularis cysts

¦he cestode is more resistant to chemotherapy ¦REA¦-EN¦ ANM CON¦ROL

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c ÕY

Resistant to praziquantel; Albendazole has some effect

Avoidance control of rodent population ********************************************************

³With all your heart you must trust the Lord and not your own

judgment Always let Ôim lead you, and Ôe will clear the road for you to follow Proverbs 3:5-8

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S4 L4 Cestodes

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