phylum platyhelminthes students copy356122

8/13/2019 Phylum Platyhelminthes Students Copy356122

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INTESTINAL

FLUKES


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Fasciolopsis buski COMMON NAME

DISEASE

GEOGRAPHICAL DISTRIBUTION

Asia and the Indian subcontinent, especially in areaswhere humans raise pigs and consume freshwater plants

HABITAT

1stINTERMEDIATE HOST

2ndINTERMEDIATE HOST

Trapa natans, Eliocaris tuberosa (____________)


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Fasciolopsis buski MORPHOLOGY

Adult Large fleshy or broadly ovate or more often appears as elongately ovoidal,

measuring from 20-75 mm

Integument is spinose, there is no cephalic cone

Oral sucker is about 0.5 mm, and the ventral sucker is 2-3mm

Intestinal ceca is unbranched and has characteristic identifications

Has a pair of highly dendritic testes which are found one after the other inthe posterior half of the fluke

Branched ovary lies to the right of the midline and opposite it is the coileduterus

Ova

Almost identical with the ova of F. hepatica Measure from 130-150u x 80-85 u

__________________________________when laid

Yolk granules are evenly distributed throughout the egg (In F. hepatica thereis___________________________)


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Fasciolopsis buski EPIDEMIOLOGY

Infection in man is through ingestion of infected raw water vegetations

PATHOGENESIS

Fasciolopsiasis Weight loss

Anemia

Diarrhea

Toxic product of this parasite produces the so-called_________________________

Larval stage of F. buski upon escaping from their cysts in theduodenum mature into adult stage within a period

of____________ Damaged produced is traumatic, obstructive, and toxic.

Adult flukes may obstruct food passages, but what is moreimportant is the sensitization and toxic effects which may resultfollowing absorption of the worms metabolite into the system


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Fasciolopsis buski DIAGNOSIS

Ova and sometimes adults are found in feces

TREATMENT Fasciolopsiasis is treatedwith praziquantel

Other good drugs are mebendazole,thiabendazole, pyrantel pamoate, oxyclozanide,nitroxynil and hexachlorophene.

Black walnut green hull is a good natural herbagainst adult worms whereas wormwood herbkills effectively larvae.

PREVENTION Freezing vegetables below ___________for a

few days or heating them above__________kills most parasites and their eggs.Drinking water can be filtered or boiled (inareas of poor sanitation). Additionally human orpig feces should not be used as a fertilizer inagriculture.


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Echinostoma ilocanum COMMON NAME

DISEASE

Echinostomiasis (____________________)


Worldwide, but human cases are seen most-frequently in southeast Asiaand in areas where undercooked or raw freshwater snails, clams andfish are eaten.

HABITAT

____________________________________


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Echinostoma ilocanum 1STINTERMEDIATE HOST

Gyraulus convexiusculus(_____________________)


Pila conics or Pila luzonica

(_______________)

MORPHOLOGY

Adult: Colarette spines, coiled

uterus, lobate ovary, dumbell testes

in tandem, medium sized folliclesvitellaria

Ova: Straw colored, operculated

and immature when laid measuring

about 83-116 u, broadly ovoidal in

shape with the presence of adistinct germ ball


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Echinostoma ilocanum

DIAGNOSIS Recovery of unembryonated egg of the parasite

in the hosts stool

TREATMENT

Praziquantel

PREVENTION

Refrain from eating raw snails in endemicareas


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Echinostoma malayanum


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MORPHOLOGY Stool samples from 8 (11.4%) patients had large (120

130 m 8090 m), brownish, operculated eggs;

3 had a total of 13 adult flukes.

Microscopy showed small leaflike flukes 89 mm longand 2.53.5 mm wide.

After the organisms were processed and stained withaceto-carmine and fast green stains, diagnostic

features of Echinostoma malayanum(Leiper 1911)were noted.


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MORPHOLOGY Adult trematodes were within known species size range (510 mm

2.53.0 mm) and had elongated bodies and bluntly rounded ends

Ventral sucker (acetabulum) was prominent and larger than theanterior oral sucker.

Paired testes were deeply branched and positioned high in theposterior half of the body, extending above the midplane with asingle anterior globular ovary.

Uterus was entirely anterior to the ovary, and vitellaria (glands)were abundant along both lateral portions of the worm, ending justposterior to the esophagus.

Oral sucker had a horseshoe-shaped anterior collar with 43circumoral spines, which differentiates this species from E. ilocanum(4951 collar spines), another trematode species endemic to thePhilippines.


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INVESTIGATION ON TRANSMISSION: In terms of eating habits, patients reported that fish were

commonly eaten raw, after being dipped in a salt and vinegarmixture, locally known as kinilaw.

Other methods of fish preparation were tinola(boiled),ginataan

(stewed in coconut milk), and sinugba(charcoal-grilled). Allechinostome-infected patients had a history of having eatensnails, kuholand kiambu-ay, prepared raw with coconut milk andlime juice (kinilaw), especially when found in greater abundanceduring the rainy season.


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INVESTIGATION ON TRANSMISSION: Human echinostome infection results from ingestion of

metacercariae that encyst in secondary intermediate hosts, usuallyfreshwater snails, tadpoles, or fish.

E. malayanumuses various species of gastropod mollusks for

primary and secondary intermediate developmental stages

Certain species of fish may also serve as secondary intermediatehosts

Several mollusks that may serve as primary and secondaryintermediate hosts have been identified in the Philippines, includingLymnaea (Bullastra) cumingiana, Radix quadrasi, and Physastrahungerfordianafor E. malayanum, and Pila luzonicafor E. ilocanum


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THE HETEROPHYIDS

CHARACTERISTICS IN GENERAL1. Smallest but considered as the ____________of all

trematodes

2. _______________ in shape measuring 1-2 mm

3. Rounded posteriorly and attenuated anteriorly with their

cuticle surrounded by fine ____________ spines4. Provided with oral, ventral, and genital sucker

5. With ________________surrounding lip of the genitalsucker which is surrounded by spines

6. Endemic in the _________________________

7. Diagnosis is based on the recovery of the eggs in stool

8. Treatment for all species is tetrachloroethylene

9. Prevention is by abstinence from eating raw or salted mulletor other infected fresh- or saltwater fish


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THE HETEROPHYIDS

Eggs out in

feces

Body of water

Larval development

S-R-C

Ingestion of inadequatelycooked fish


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THE HETEROPHYIDS

HETEROPHYIDS OFMEDICALIMPORTANCE

Heterophyes heterophyes

Metagonimus yokogawai


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Heterophyes heterophyes DISEASE


Egypt, the Middle East, and Far East

1stINTERMEDIATE HOST


HABITAT

Adult worm inhabits the


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Heterophyes heterophyes


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Heterophyes heterophyes PATHOGENESIS, PATHOLOGY AND SYMPTOMATOLOGY

Mild inflammatory reaction at sites where the minute worms become attachedto the intestinal mucosa or burrows into the mucosa

Worms produce mild irritation, accompanied by colicky pains and mucoiddiarrhea, with production of excess mucus and a superficial necrosis of themucous coat

Ova may filter thru the intestinal wall, picked up by the mesenteric lymphaticsand are filtered out in cardiac valves and myocardium, where they provoke tissuereactions leading to cardiac failure

Ova may also be carried to the brain with the production of fatal cerebralhemorrhage

There is usually a significant diarrhea but no erythropenia in Heterophyesinfection


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Metagonimus yokogawai COMMON NAME

DISEASE


Mostly the Far East, as well as Siberia, Manchuria, the Balkanstates, Israel, and Spain.

M t i


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Metagonimus

yokogawai

MORPHOLOGY

Adult Almost similar with H.

heterophyesexcept for

FUSION OF THE

VENTROGENITALSUCKERS and

DEFLECTED towards on

the side of the body, pair

of testes, one bigger than

the other

Ova Similar with H. heterophyes


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LUNG

FLUKE


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Paragonimus westermani COMMON NAME

DISEASE

Paragonimiasis,


Paragonimusspp. are distributed

throughout the Americas, Africa andsoutheast Asia. Paragonimus westermaniisdistributed in southeast Asia and Japan.

Endemic in the Philippines particularly in


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Paragonimus westermani MORPHOLOGY

Adult 8-12 mm

Coffee bean-shaped

Provided with oral sucker, ventral sucker which is situated midway in the

body,

Simple intestinal ceca with several indentations (zigzag)

2 lobed testes situated side by side in the posterior region

Right side of the ventral sucker is a coiled uterus and opposite it is the lobed

ovary

Vitellaria is highly branched starting from the region of the pharynx down to

the posterior end

Long excretory bladder extending from below the level of the pharynx downto the posterior end

Ova Measure about 80u, immature when laid, has


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Paragonimus westermani


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Paragonimus westermani EPIDEMIOLOGY

Natural DH other than man includes Infection is obtained through ingestion of inadequately cooked

_______________________________________________

in the endemic regions

PATHOGENESIS PATHOGENIC STAGE:

INFECTIVE STAGE:

Immature adults May cause ______________________which lead to abscess production

Mature adults Produce lesions where they are found

In the lungs, they produce an inflammatory reaction which lead to cysticencapsulation filled with blood tinged purulent materials with flecks of reddishbrown material containing feces


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Paragonimus westermani

PATHOGENESIS Adult flukes living in the lung

cause lung disease that maynever be diagnosed or isthought tobe_____________________

After ___________days, theinitial signs and symptoms maybe diarrhea and abdominal pain.

This may be followed severaldays later by fever, chest pain,and fatigue.

The symptoms may alsoinclude a

_____________initially, whichlater often becomes productivewith

_________________________________sputum onexertion


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Paragonimus westermani DIAGNOSIS

Ova are found in sputum after KOH digestion or in feces after formol-ether concentration technique

Serological tests: CF or ELISA

Chest X-ray and lung biopsy

TREATMENT Praziquantelis the drug of choice: adult or pediatric dosage, 25 mg/kg given orally3 times per day for 2 consecutive days. Alternatives: Triclabendazole(not availablein the U.S.), adult or pediatric dosage, 10 mg/kg orally once or twice; or Bithionol:adult or pediatric dosage, 30-50 mg/kg on alternate days for 10-15 doses. Forcerebral disease, a short course of corticosteroids may be given with thepraziquantel to help reduce the inflammatory response around dying flukes.

PREVENTION Never eat raw freshwater crabs or crayfish.

Cook crabs and crayfish for to at least 145F (~63C).

Travelers should be advised to avoid traditional meals containingundercooked freshwater crustaceans.


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DIOECIOUS FLUKES


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BLOOD

FLUKES


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BLOOD FLUKES

Characteristics1. Elongately cylindroidal in shape with prominent oral and

ventral suckers

2. Have separate sexes (dioecious)

3. Abscess of muscular pharynx

4. Intestine bifurcates and unites at a certain level

5. Male adult are provided with gynecophoral canal on theventral side, the function of which is to cuddle the femalethroughout its entire life except during oviposition, since theyare always in perpetual copula, known as

the_______________________6. Life span may be as long as __________________

7. Only trematodes found in_____________________, canalso be isolated in urine and/or stool


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BLOOD FLUKES

Characteristics8. Ova are embryonated and _______________________

9. Only trematodes that require only _________________

10. Does not have _________________________

11. Infective stage is _________________ which has acharateristic ___________________ appearance

12. Manner of transmission:_______________________________________

13. Majority of the schistosomes are parasitic in the lower animals.

Only 3 are of medical importance to humansa. Schistosoma japonicum

b. Schistosoma mansoni

c. Schistosoma haematobium


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Schistosoma japonicum COMMON NAME

SYNONYMS__________________________________

DISEASE Schistosomiasis japonica, Oriental schistosomiasis

GEOGRAPHICAL DISTRIBUTION S. japonicumin the Far East

HABITAT ______________________________________________and

occasionally in the inferior mesenteric and portal venous system

Schistosoma japonicum


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Schistosoma japonicum

MORPHOLOGY Male adult

12-20 mm and 0.5 mm in diameter

Oral and ventral suckers are located near the anterior end of the worm

Considered as the biggest of all blood flukes

Cuticles are smooth and non-tuberculated

6-8 testes arranged in rows

Intestinal ceca bifurcates then fuses very posteriorly ( very late union)

Female adult 26mm x 0.3 mm ( longer and more slender)

More than one esophageal bulb, with fine cuticles

Ovary is located centrally

Uterus is long and well-developed with 50-100 eggs, female is usually found held

in the gynecophoric canal of the male; females are capable of laying about 1,5003,000 eggs per day (most destructive)

Ova 73-100 x 50u, broadly ovoidal in shape with very characteristic cellular debris; it

has a rudimentary or abbrevated lateral knob, shell is stained with acid fast, slopingshoulder miracidium inside


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S hi j i


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Schistosoma japonicum PATHOGENESIS, PATHOLOGY, AND

SYMPTOMATOLOGY

4 STAGES1.____________________________________________________

May last up for a few weeks up to several months

Initially there is sub-irritation produced at the site of penetration causing

dermatitis and rashes (swimmers itch, clam digger ithc, urticarial rash)

In the clamdigger itch urticarial hemorrhages,

In lungs, produce petechial hemorrhages, causing cough hemoptysis, and

chest pain

In the liver, may produce hepatitis, growth within interhepatic blood

vessels

S hi j i


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SYMPTOMATOLOGY

4 STAGES2.___________________________________________________

Initial changes due to eggs causing acute suppurative vascular

inflammation leading to small microabscess formation

If near the surface, they will rupture into the lumen together with the

eggs producing schistosomal colitis or ulcerative colitis depending on thenumber of worms present and the amount of sensitization produced

Characterized by dysenteric syndrome

Diarrhea, which last for 6 weeks, is mucoid, scanty, and streaked with

blood, it involves the lower GIT, aside from frequent bowel movement,

theres also tenesmus, abdominal pains or cramps

Diarrhea is not responsive to any anti-diarrheal theraphy

Usually no fever, unless secondary bacteria infection occured

S hi t j i


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SYMPTOMATOLOGY

4 STAGES3.______________________________________________

Initiate fibrotic reaction, scarring of the infected areas

S/S of diarrhea disappear, eggs seldom recovered from stool

Worms lay their eggs in other areas, can also be carried to thedifferent parts of the body forming tubercle and granuloma

Splenomegaly, hepatomegaly and impairment of liver function andmarked fibrosis of the affected areas

Ascitis

Loss of appetite Pedal edema

S hi t j p i


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SYMPTOMATOLOGY

4 STAGES

4. ____________________________________________

After a long period, granuloma of the affected portion lead to fibrosis(periportal) leading to portal cirrhosis due to embolic closure ofportal radicles with eggs

Toxic metabolites secreted by the adults and the continuousinfiltration of eggs

Cirrhosis later produce portal hypertension causing s/s like ascitis(decrease albumin and decrease oncotic pressure), splenomegaly(hypersplenism decrease platelets, decresease wbc and rbc),

distended abdominal veins, hemorrohoids, esophageal varices(hematemesis, hematofezia)

Marked abdominal enlargement

Liver become small

S hi t j p i


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Schistosoma japonicum DIAGNOSIS

Incubation stage_________________________

Early egg deposition stage-________________________

________________________ Late egg deposition and tissue

proliferationstage_____________________

________________________

________________________________________________________________________

S hi t j p i


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Schistosoma japonicum TREATMENT

Tartar emetic (Potassium Antimony tartrate)

Specification essential for successful treatment of S. japonica Patient should be in a relatively early stage of the disease, before irrepairable

damage to the liver and other vital organs has taken place

Should be protected from re-exposure

Given the benefit of nutritious food to build up resistance

Treated thoroughly with tartar emetic and re-treated on slight recurence

Liver function tests should be conducted during the course of the treatment tocheck for any hepatoxic damage caused by the drug

Drug of choice is praziquantel for infections caused by all Schistosomaspecies. Oxamniquine has been effective in treating infections caused by S. mansoniinsome areas in which praziquantel is less effective.

PREVENTION

Allow night soil to ripen longer in containers, or to disinfect it with fertilizer salts(ammonium nitrate) in order to kill the eggs before the fertilizer is spread on thefields

Use mulusciscides

Community sanitation

S hi t i


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Schistosoma mansoni COMMON NAME

DISEASE

Mansons intestinal schistosomiasis or bilharziasis


Schistosoma mansoniis found in parts of South America and theCaribbean, Africa, and the Middle East

HABITAT

S hi t i


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Schistosoma mansoni MORPHOLOGY

Male adult

6-12x1mm Coarse tuberculation, Lateral margins interlock and are held in position by

accuminate spines which are longer than the otherintegumentary ones, minute sensory papilles aredistirbuted over the surface

Tuberosities are provided with microscopic tufts ofhair

Early union of the intestinal ceca 8-9 small testes arranged in clusters (in some books

3-13 small testes)

Female adult 7-17 x 0.25mm One esophageal bulb, early union of intestinal ceca Ovary located anteriorly with a short uterus

containing 4 eggs

Females are capable of laying 100-300 eggs per day

Ova 114-175u and has a very prominent lateral spine


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Schistosoma mansoni


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Schistosoma mansoni

INTERMEDIATE HOSTS

Australorbis, Biomphalaria, Planorbis

INFECTIVE STAGE

Fork-tailed cercaria

PATHOGENIC STAGE Ova


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Schistosoma mansoni


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Schistosoma mansoni PATHOGENESIS

Lesions produced similar to S. japonicum except for the much smaller number ofeggs and the delay in the ____________________________production

around the egg

Organs and tissues most seriously involved are the colon and rectum, but eggs

are carried in the mesenteric current into the portal vessel filter in the

periportal tissues within the liver and set up the pathologic processes leading to

hepatic cirrhosis

Incubation stage- initial papular rash with pruritus, enlarged, and sometimes

tender liver; diarrhea

Period of egg deposition of extrusiontakes place 5-7 weeks after exposure,

accompanied by schistosomiasis dysentery, with blood and mucus in feces; later

intestinal wall becomes inflamed, thickened and fibrosed, with abscess opening

thru the mucosa, and with hyperemia of the peritoneal coat, theres development

of paillomata and prolapse of rectum, liver and spleen are enlarged and tender

Period of tissue proliferation and repair- tone of the intestinal wall diminished

Schistosoma mansoni


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Schistosoma mansoni PATHOGENESIS

Pulmonary complications ____________________following migration of the metacercariae thru the

lungs

_____________________simulating late TB with endarteritis of pulmonaryvessels

_____________________terminating in congestive heart failure

DIAGNOSIS Recover of eggs from urine or feces (more in feces); COPT, CFT, intradermal test

TREATMENT

Drug of choice is praziquantel for infections caused by all Schistosomaspecies. Oxamniquine has been effective in treating infections caused by S. mansoniin

some areas in which praziquantel is less effective.

PREVENTION

Same as with S. japonicum

Schistosoma haematobium


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Schistosoma haematobium COMMON NAME

DISEASE

Vesical schistosomiasis, schistosomiasis haematobia, vesical orurinary bilharziasis, schistosomal hematuria


S. haematobiumin Africa and the Middle East

HABITAT



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Schistosoma haematobium MORPHOLOGY

Male adult Shorter, stouter, organism

10-15x 0.8-1mm

Fine tuberculation, 2 suckers (Ventral is larger)

Behind the ventral sucker the body of the male is infolded ventral all the way

to the caudal extremity to from the gynecophoral canal

There is late union intestinal ceca

4-5 testes arranged in clusters or columns

Female adult Long and slender

20-0.25mm, suckers are small, subequal and are not conspicuosly muscular

Ovary located at the posterior end with a long uterus containing 20-30 eggs,

Capable of producing 20-290 eggs per day

Ova Measures about 120 u and provided with a very characterized terminal spine


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Schistosoma haematobium INTERMEDIATE HOSTS

Bulinus, Planorbis

PATHOGENESIS Generalized and localized

reaction__________________________________

Trauma, with hemorrhage, aseggs_____________________________________________________

Pseduo-abscess and pseudo-tubercle formation aroundeggs lodged in perivascular tissues

DIAGNOSIS Recovery of eggs from urine and stool ( more in urine),

aspirated materials from cystoscope, proctoscope,Fairleys complement fixation test, COPT in chronic

areas

TREATMENT AND PREVENTION: Same withthe other schistosomal infections

END OF FINALS LECTURE


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END OF FINALS LECTURE

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