notes

1. Fasciolopsis
buski
“Large intestinal
fluke”
Echinostoma
ilocanum
“Garrison’sfluke”
Artyfechinostomum
malayanum
Heterophyes
heterophyes
Metagonimus
yokogawai
Nanophyetus
salmincola
“Salmon poisoning
fluke”
Gastrodiscoides
hominis
Disease Fasciolopsiasis Echinostomiasis Heterophyiasis Metagonimiasis Gastrodiscoidiasis
Definitive host Humans,hogs, &
dogs
Humans,aquatic
birds, dogs, cats,rats
& pigs
Humans,aquatic
birds, dogs, cats,rats
& pigs
Humans,
domesticated& wild
fish-eating mammals
Humans,dogs, cats,
hogs, pelicans,other
fish-eating birds
Humans,dogs, cats &
wild fur-bearing
mammals
Humans,hogs, &
napu mouse deer
Habitat Small intestine
(Duodenum &
Jejunum)
Small intestine Small intestine Middle part ofSmall
intestine
Upper/Middle
Jejunum rarely
duodenum, ileum &
cecum
Small intestine Large intestine –
Cecum & ascending
colon
Primary IH Planorbid Snails
Segmentina,
HIppeutis, &
Gyraulus
Gyraulus
convexiusculus &
Hippeutis umbilicalis
Not known Brackishwater snails
Pirenella inEgypt
Cerithidea inJapan
Snails
Semisulcospira,
Thiara, Hua
Goniobasis &
Oxytrema silicula
Snails
Secondary IH Water caltrop,
Hyacinth Eichornia,
w ater chestnut,
w ater bamboo,
Zizania, w ater
morning glory &
lotus
Pila luzonica (kuhol)
Vivipara angularis
(susong pampang)
Birabid /cumingiana
Lymnaea/bullastra
30 species of
brackish/freshwater
fish including
Mugil(mollet),
Tilapia,
Acanthogobins
Fresh water
salmonoidfishes &
cyprinoids
(richardsonium,
odoutobutis
Salmonoid
fishes(Piscinehosts)
Aquatic vegetation
Cercariae Liberated in w ater
fromsnail 4-7
w eeks after
infection
After 42-50 Encysts as
metacercariaeon
scales,gills, fins, tail
or less frequently the
muscles offishes
Elongate, Spinous
body, Lontg tailw/
dorsoventralflutings
Encysts as
metacercariaeon
scales,gills, fins, tail
or less frequently the
muscles offishes
Metacercariae I-nner w allsoluble
in digestive juices
-Resistant to cold
-Dessication at
summer
temperatures
Wall is dissolvedin
duodenum&
ruptured by activated
larva
Adult worm in 25-30
days
Adult worm in 5 days
or more
Epidemiology
-Central & South
China, Yangtze
valley, Taiw an,
Thailand, Laos,
Vietnam,
Combodia, India,
Korea, Indonesia
-Chief Endemic
Area Kw angtung &
Chekiang provinces
of china
Southeast& East Asian countries -Egypt(lower Nile
valley), Greece,
Israel, Central&
south China, Japan,
Korea, Taiwan, &
Philippines
-Chief Endemic
Area Kw angtung &
Chekiang provinces
of china
Far east, China,
Japan, korea,Taiwan,
Philippines, Siberia,
The Blakans,Greece,
& Spain
Siberia &Pacific
coast ofNorth
America
Acts as a reservoir
host ofNeorickettsia
helminthica
Assam, Bengal,
Malaya,andVietnam

2. Pathology -Inflammation,
Ulceration, &
Abscesses at site
of attachment
-Heavy infections:
Edma, ascites, &
anasarca
-Intesinal stasis &
obstruction
-Inflammation at siteofattachment
-Ulceration, Diarrhea(Sometimes bloody),
Abdominalpain
-Absorptionofmetabolites ofworms =
general intoxication
Heavy infections =
irritationofintestinal
mucosa,may result
in chronic
intermittentmucous
diarrhea w/ colicky
pains, abdominal
discomfort&
tenderness
-Eosinophilia w/o
anemia
Similar to
Heterophyiasis
-Eggs may enter
lymphatics or
mesentericvenules
set up granulomatus
lesions insuch
distantfocias the
heart and nervous
system
Asymptomatic but
some havediarrhea,
abdominal
discomfort&
peripheral blood
eosinophilia
Diarrhea
Lab dx Finding Eggs in
feces
-Adult flukes
sometimes vomited
Finding Eggs in feces Finding Eggs in feces but require differentiation fromClonorchis,
Ophisthorchis & other heterophyid flukes
Finding Eggs in
feces
Tx Praziquantel
Morpholody Egg – Ellipsoidal
-Yellow ish w/ clear,
thin shell , &
opercualted
-Underdeveloped
w hen passed in
feces
Adult fluke – Flesh
colored w orms
-Cuticle- transverse
row s of small
spines destroyed
by intestinal juices
-Oral sucker ¼ size
of ventralsucker
-Intestinal tract:
Short prepharynx,
bulbous pharynx,
short esophagus,
-Pair of ubranched
ceca, 2
characteristic
lateral indentations
-2 dendritic testes
in posterior half of
w orm
-Single branched
ovary middle of the
body to the right of
the midline
-Vitellaria lateral to
ceca extend from
ventralsucker to
Egg- Straw-colored
operculated
Adult fluke-
Reddish-gray
2.5-6.6mmx 1-
1.35mm
-Tapered atposterior
end. 49-51 collar
spines around oral
suckers
-Oral sucker in center
ofcircumoral disk &
ventral sucker at
anterior 5th ofbody
-Simple intestinal
ceca
-2 testes deeply
bilobed at 3rd quarter
ofthe body
-Ovary locatedin
front ofanterior
testis
-Follicular vitellariain
posterior half ofbody
* uterinecoils
betweenovary &
ventral sucker
Egg- Larger than E.
ilocanum, golden
brown & operculated
120-130umx80-90um
Adult fluke-
5-12mmx2-3mm
Rounded posterior
w/ 43-45 spines
around oral suckers
-2 testes largew/ 6-9
lobes
-Ovary is small.
Rounded or oval
anterior to the testes
& preequatorial
Egg- Light brown,
thick-shelled,
operculated
29x16um
-Fully developed
miracidia
-Slight shoulder at
rim ofoperculum
sometimes a knobat
posterior pole
Adult fluke-Small
1.3x0.5mm
Pyriform, grayish,
cuticlecovered w/
fine scale-likespines
-Large ventral sucker
in anterior middle3rd
ofbody
-Protrusible,
nonadhesivegenital
sucker atleft
posterior border of
ventral sucker
-2 ovoid testes side
by side in posterior
5th ofbody
Egg- light yellow-
brown thin shelled
operculatedw/
nodular thickening
on posteriorend
28x17um
Contain mature
miracidia
Adult fluke-
Small 1.4x0.6mm
Pyriform w/ rounded
posterior & tapering
anterior end
-cuticle covered w/
minute scale-like
spines numerous at
anterior end
-large ventral sucker
to right ofmidlineof
the body
-2 oval testes,
obliquely sideby side
posterior 3rd ofbody
-Globose ovary at
junction ofmiddle
and lowerthird of
body
-Coarse vitellaria ina
fan-shaped
distributionin
posterior lateral
Egg- Yellowish,
broadly oval,
operculate,thick-
shelled
- 70x42um
-Contain
Underdeveloped
miracidia
Adult fluke-
0.9x0.4mm
Pyriform w/ unarmed
suckers
Uterus contains 10-
15 eggs
Egg- Greenish-brwon
150-170 x 60-70um
Ovoid w/ anterior
portion narrow &
small operculum
Unembryonated
when passed
Matures 16-17days
at 27-34C resembles
F.buski butnarrower
Adult fluke-Reddish,
aspinous, dorsally
convex
-5-8x3-5mm
Anterior conical
portion & enlarged
posterior disk w/
large ventral sucker
w/ a thick,
overhanging rim
-ceca areshort
extending only to
middle ofdiscoid
region
-Lobate testes liein
tandem below
bifurcation ofthe
ceca

3. posterior end of
body
fields
Life span: 1 year