about helminth

1. Presented by
ABID HUSSAIN
Abdul Wasey

2.  Metagonimus is a genus of family Heterophyidae.
 Cause disease Metagonimiasis.
 Metagonimiasis was discovered by Katsurasa in
1911-1913 when he first observed eggs of M.
yokagawai in feces .
 M. takahashii was described later first by Suzuki in
1930
 M. Miyatai was describe in 1984 by Saito
 All three species are hermaphrodite.
 Smallest intestinal fluke

3. Classification
Kingdom Animalia
Phylum Platyhelminthes
Class Trematoda
Order Opisthorchiida
Family Heterophyidae
Genus Metagonimus
species Metagonimus yokogawai

4.  Metagonimiasis infections are endemic or
potentially endemic in following countries
including
 Japan, Korea, China, Taiwan, the Balkans,
Spain, Indonesia, the Philippines , Russia,
India and Pakistan

5.  Metagonimus yokagawai also called
the Japanese fluke
 Metagonimus Takahashii
 Metagonimus miyatai

6. Transmission requires two intermediate hosts,
 The first of which is snails, most commonly of
species Thiara granifera.
 Infection is acquired through the secondary
intermediate host, fish, that haven’t been
thoroughly cooked. Metacercariae encyst under
the scales or in the flesh of fish
Definitive hosts include humans and various fish-
eating mammals, primarily dogs, cats, and pigs.
Fish-eating birds may also be infected with
metagonimiasis

7.  Eggs are very small. Eggs have a
smooth, hard shell that is transparent and
yellow-brown in color, ovoid egg shape.
 They are about 26-28 μm length and 15-
17μm width.
 The egg also has a very slight opercular
shoulder

8.  leaf-shaped.
 It is one of the smallest intestinal flukes, its
ventral sucker is deflected to the right of its
midline and is closely associated with the
opening of the genital pore.
 The testes are large and diagonal to each
other
 Ovary is anterior to the testes and the
uterus is filled with eggs. The uterus is the
largest organ in the body.
 The size of the adult fluke is 2.5 mm length
by .75 mm width.

10. oral sucker (OS), pharynx (PH), intestine
(IN), genitoacetabulum (GA), ovary
(OV), the large, paired testes (TE), and
eggs within the uterus (EG).

11. Life cycle
Adults release fully embryonated eggs each with a fully-
developed miracidium, and eggs are passed in the host’s
feces
 After ingestion by a suitable snail (first intermediate
host), the eggs hatch and release miracidia which
penetrate the snail’s intestine
 The miracidia undergo several developmental stages in
the snail, i.e. sporocysts , rediae , and cercariae. Many
cercariae are produced from each rediae. The cercariae
are released from the snail
 It is encyst as Metacercariae in the tissues of fish (second
intermediate host)
 The definitive host becomes infected by ingesting
undercooked or salted fish containing Metacercariae
 After ingestion, the Metacercariae excyst, attach to the
mucosa of the small intestine and mature into adults

14. Pathogenesis
 It cause Metagonimiasis
 Site of infection is small intestine
 The incubation period is around 14 days
 Infestation may persist for more than one
year

15. Sign and Symptoms
 Diarrhea
 Abdominal pain
 Nausea
 lethargy
 anorexia
 Fatigue
 malaise
 seizures, neurologic deficits

16. Diagnosis
 Fecal test
 Serological test(Elisa)

17.  Avoid eating uncooked food in endemic
area
 Prevent fecal contamination of fish
ponds.
 Education regarding method of
transmission
 Snail control
 Avoid feeding raw fish to cats and dogs
in endemic area.

18.  Praziquantel(drug of choice)
 Tetrachloroethylene
 bithionol
 Niclosamide
 Nicoflan