FASCIOLOPSIS BUSKI
Dec 25, 2015
FASCIOLOPSIS BUSKI
Fasciolopsis buski is known scientifically as thelargest intestinal fluke in humans.Infection occursprimarily in Asia and the Indian subcontinent,especially in area where humans raise pigs and consume freshwater plants, so this helminth is also named as “giant Asian intestinal fluke”.This giant parasite has even been described as “meat worm”
or “reddish worm” in traditional Chinese medical book.
Introduction
I. Morphology(1) Adult
• Long elliptic, flesh-colored, looks like
a slice of raw meat
• The size: 20-75×8-20×0.5-3mm
• The ventral sucker (filler-like
/ infundibular ) is larger and near by the
much smaller oral sucker
• Two coral-liked(珊瑚 ) testes are located
in the posterior half of the body
No seminal receptacle
ventral sucker is 3-4 times larger than oral sucker
uterus
cecum
vitellaria
oral sucker
ovary
testes
(2) Egg
The thinner shell with an operculum (not so obvious)
encloses an ovum and 20-40 yolk cells
Slightly yellow in color
130-140×80-85µm (the largest helminth egg)
Oval / long elliptic in shape
The first intermediate host: Segmentina
water caltropwater caltrop 水红菱水红菱 茭白 cane shoot
Water chestnut荸荠
Aquatic plant vectorThe second intermediate host:
II. Life cycle
1.Site of inhabitation: small intestine,
2. Infective stage: metacercaria,
3. Infective route and mode: eating raw water
plants with metacercariae,
4. Intermediate hosts: Planorbis snail,
5. Reservoir hosts: pig,
6. Life span: 1-4 years,
7. Egg output: 15,000/worm/day.
Adolescent Adult Eggs
Duodenum In Human Body 3 months are discharged
man eats metacercariae in feces
on raw water plants ────────────────────────────Metacercaria Eggs get into water encystations on the In Water 25-30℃ surface of water plants 2-3 months 3-4weeks
Miracidia hatch out invadesMany cercaria asexual reproduction Planorbis snail Many daughter rediae Many mother rediae Sporocysts
III. Pathology and Symptomatology
1.The enteritis due to worms’ adhesion
manifests abdominal discomfort and
diarrhea.
2. Malnutrition results from the worms
sharing food with the host and diarrhea.
IV. Diagnosis
Stool examination:
1. Direct fecal smear,
2. Water sedimentation method
V. Treatment and Prevention
1. The treatment of the patients, carriers and pigs
Drug of choice is praziquantel. Other effective
drugs include hexachloroparaxylene, bithionol (bitin).
The drug for pig is dipterex (敌百虫 ).
2. Prevention
(1) Health education
(2) Deal with night soil.
(3) Avoid feeding pigs on raw water plants
VI. EpidemiologyThis disease is prevalent in Southeast
Asia,China, Japan, Korea, Thailand, Burma, Kampuch
ea, Vietnam, Bangladesh, Philippines,Indonesia, Malay
a and India
. In China it is found in 18 provinces, city and
autonomic region except north and west regions.
The prevalence of fasciolopiasis is relative to grow
ing water plants and feeding pigs
on water plants.
Thank you !