the intestinal and tissue parasitic species ofplatyhelminthes · the intestinal and tissue...

The intestinal and tissue

parasitic speciesof Platyhelminthes

The intestinal and tissue

parasitic speciesof Platyhelminthes

byPiotr NOWOSAD

byPiotr NOWOSAD

Phyllum: Platyhelminthes

(flatworms)

Phyllum: Platyhelminthes

(flatworms)

TrematodaTrematoda

flukesflukes

CestodaCestoda

tapewormstapeworms

classesclasses

Platyhelminthes (flatworms)Platyhelminthes (flatworms)

1. Trematoda (flukes), Cestoda (tapeworms);1. Trematoda (flukes), Cestoda (tapeworms);

2. Protonephridial excretory system (flame-cells);2. Protonephridial excretory system (flame-cells);

3. Sucking organs and hooks for attachment;3. Sucking organs and hooks for attachment;

4. Tegument;4. Tegument;

5. Most species are hermaphroditic.5. Most species are hermaphroditic.

The general life cycle of TrematodaThe general life cycle of Trematoda

Definitive

host

Intermediate

host2nd intermediate

host

sporocystsporocyst

rediarediacercariacercaria

eggegg miracidiummiracidium

metacercariametacercaria

adultadult

adolescariaadolescaria

furcocercariafurcocercaria

typical or accidental

The life cycle of Clonorchis sinensis (Chinese fluke)


Typical

definitive hosts

Ht

P

small (30 – 17 µm, elongated

with broad rounded posterior end

And

a convex operculum resting on "shoulders”.

A small "knob" may be seen on the posterior end.

Geographic distribution:Geographic distribution:

Endemic areas - Asia

(China, Korea, Vietnam,

Taiwan)

Endemic areas - Asia

(China, Korea, Vietnam,

Taiwan)

Non endemic areas:

USA

Non endemic areas:

USA

vittelinevitteline glandsglands

transversaltransversal vittelinevitteline

canalcanal

ootypeootype

ovaryovary

seminal receptacleseminal receptacle

uterusuterus

genital poregenital pore

The femaleThe female

reproductive organsreproductive organs

The maleThe male


testestestes

vasvas efferensefferens

vas deferensvas deferens


The life cycle of Fasciolopsis buski (Giant intestinal fluke)

adolescariaadolescaria

Typical

definitive hosts

Ht

P

Fasciolopsis buski egg. Wet mounts with iodine.

The eggs are ellipsoidal. They have a small operculum.

The operculum can be opened.

Size range: 150 µm by 90 µm.


Endemic areas – Asia and the Indian subcontinent,

especially in areas where humans raise pigs

and consume freshwater plants.

Endemic areas – Asia and the Indian subcontinent,

especially in areas where humans raise pigs

and consume freshwater plants.

The life cycle of Paragonimus westermani (Lung fluke)


Typical

definitive hosts

Ht

P

Egg of Paragonimus westermani.The average egg size is 85 µm by 53 µm.They are yellow-brown, ovoidal or elongate, with a thickshell, and often asymmetrical with one end slightlyflattened.At the large end, the operculum is clearly visible.The opposite (abopercular) end is thickened.The eggs of P. westermani are excreted unembryonated.

LABORATORY DIAGNOSISLABORATORY DIAGNOSIS

MICROSCOPIC IDENTIFICATIONof eggs in stool or sputum, but these are not present until 2 to 3

months after infection (eggs are also occasionally encountered in

effusion fluid or biopsy material). Concentration techniques may be

necessary in patients with light infections.

ANTIBODY DETECTIONis useful in light infections and in the diagnosis of extrapulmonary

paragonimosis.


P. westermani occurs in the Far East and Africa.P. westermani occurs in the Far East and Africa.

Schistosoma: haematobium

mansoni

japonicum

�The sexes of Schistosoma are separated;

�Males differ morphologically from females;

�Adult parasites are elongated and round;

� In the life cycle new stages occur:

furcocercariae and schistosomula.

�The sexes of Schistosoma are separated;

�Males differ morphologically from females;

�Adult parasites are elongated and round;

� In the life cycle new stages occur:

furcocercariae and schistosomula.

The life cycle of Schistosoma

Man is the typical

definitive hosts

furcocercariafurcocercaria

Ht

M/P

The habitats of:The habitats of:

S. haematobium

the veins of the urinary bladder

S. haematobium

the veins of the urinary bladder

S. mansoni

the veins of the rectum

S. mansoni

the veins of the rectum

S. japonicum

the veins of the small intestine

S. japonicum

the veins of the small intestine

The diagnosis of schistosomosis consist in:The diagnosis of schistosomosis consist in:

� microscopic identification of the eggs

in urine or stool;

� examination of biopsies tissue;

� immunological tests.

� microscopic identification of the eggs

in urine or stool;

� examination of biopsies tissue;

� immunological tests.


S. mansoni = parts of South America, Africa,

and the Middle East;

S. haematobium = Africa and the Middle East;

S. japonicum = the Far East.

S. mansoni = parts of South America, Africa,

and the Middle East;

S. haematobium = Africa and the Middle East;

S. japonicum = the Far East.

The body consist of:

scolex, neck and proglottids.

The scolex may be equipped with:

bothria, acetabulas and hooks.

Proglottids: immature, mature and gravid.

Naval Medical School

3. STROBILA

2. NECK

1. SCOLEX

TapewormsTapeworms ((CestodaCestoda))

The life cycle of Diphyllobothrium latum

Typical

definitive hosts

plerocercoidplerocercoid

coracidiumcoracidiumprocercoidprocercoid

Ht

P

The diagnosis of diphyllobothriosisThe diagnosis of diphyllobothriosis

The eggs are oval or ellipsoidal, with an

operculum at one end (arrows).

At the opposite end is a small knob.

Size range: 58 to 76 µm by 40 to 51 µm.

The eggs are oval or ellipsoidal, with an

operculum at one end (arrows).

At the opposite end is a small knob.

Size range: 58 to 76 µm by 40 to 51 µm.

vittelinevitteline

glandsglands

uterusuterus

The femaleThe female


The maleThe male


testestestes


vaginavagina

Mature proglottid of D. latum is wider than longMature proglottid of D. latum is wider than long

The life cycle of Taenia solium and T. saginata

T. T. saginatasaginata T. T. soliumsolium

Definitive host; small

intestine is a habitat

cysticercus larvacysticercus larva

Ht

M

The eggs of Taenia saginata and T. solium are

undistinguishable morphologically (31 to 43 µm).

The eggs of Taenia saginata and T. solium are

undistinguishable morphologically (31 to 43 µm).

T. saginataT. saginata T. soliumT. solium

15-30

lateral

branches

15-30

lateral

branches

7 (8) - 12

lateral

branches

7 (8) - 12

lateral

branches

The life cycle of Taenia solium and T. saginata

T.T. saginatasaginata T.T. soliumsolium

Intermediate host

cysticercus larvacysticercus larva

The life cycle of Hymenolepis nana

monoxenous

homoxenous

monoxenous

homoxenous


small intestinesmall intestine

villivilli

oncospheresoncospheres

cysticercoidcysticercoid

The eggs are oval or

subspherical;

(size 40-60 µm x 30-50 µm),

On the inner membrane are two

poles, from which 4 to 8 polar

filaments spread out between the

two membranes.

The eggs are oval or

subspherical;

(size 40-60 µm x 30-50 µm),

On the inner membrane are two

poles, from which 4 to 8 polar

filaments spread out between the

two membranes.

Gravid proglottids of H. nanaGravid proglottids of H. nana

Uterus in gravid proglottid

is baggy and contains

many eggs.

Uterus in gravid proglottid

is baggy and contains

many eggs.

The life cycle of Echinococcus granulosus

The life cycle of Echinococcus granulosus

Hydatid cyst

(bladder larva)

Hydatid cyst

(bladder larva)

Hydatid cystHydatid cyst

The diagnosis of echinococcosis (hydatidosis)

consists in:

The diagnosis of echinococcosis (hydatidosis)

consists in:

� several immunological tests;

� founding hydatid cyst during medical

examination such as USG, CT, X-ray;

� fine-needle biopsy.

� several immunological tests;

� founding hydatid cyst during medical

examination such as USG, CT, X-ray;

� fine-needle biopsy.

stalk

path of exit of the scolex

hooks

suckers

150 150 µµmm

0 µm0 0 µµmm

0 µm0 0 µµmm

80 µm80 80 µµmm

the intestinal and tissue parasitic species ofplatyhelminthes · the intestinal and tissue...

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