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)
metacercariametacercaria
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
reproductive organsreproductive organs
testestestes
vasvas efferensefferens
vas deferensvas deferens
genital poregenital pore
vittelinevitteline glandsglands
transversaltransversal vittelinevitteline
canalcanal
ootypeootype
ovaryovary
seminal receptacleseminal receptacle
uterusuterus
genital poregenital pore
The femaleThe female
reproductive organsreproductive organs
The maleThe male
reproductive organsreproductive organs
testestestes
vasvas efferensefferens
vas deferensvas deferens
genital poregenital pore
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.
Geographic distribution:Geographic distribution:
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)
metacercariametacercaria
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.
Geographic distribution:Geographic distribution:
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 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.
Geographic distribution:Geographic distribution:
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 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 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
reproductive organsreproductive organs
The maleThe male
reproductive organsreproductive organs
testestestes
genital poregenital pore
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
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 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.