trematodes 华支睾和卫氏并殖吸虫.pdf

2012-9-20
Human Parasitology
For 8-year medical students
人体寄生虫学
Wu Zhongdao, Ph.D
Professor
Department of Parasitology
Tel: 87331588
wuzhd@mail.sysu.edu.cn

Prof Lv Fangli(吕芳丽)
Prof Li Xiurong(李学荣)
Prof Fung Mingchiu(冯明钊), Ph.D,
(Hong Kong Chinese University)
Associate Prof Wang Xuelan(汪雪兰)

Prof. Dr. Heinz Mehlhorn
Parasitologist
Heinrich Heine University
(德国杜塞尔多夫大学)

Curriculum of Human Parasitology 2012
1. Lecture: Sept 20—Jan 7
2 hr each week
Total 33 hr
2. Practice in Laboratory: Nov 20~Jan 8
3 hr each week
Total 24 hr
3. TBL & learning by yourself
4. Test: homework, final test

Textbook and reading books:
Textbook of Medical Parasitology, Edition by Wu
Zhongdao, Lv Fangli and Zheng Xiaoying.The book
can be ordered at the Department of Parasitology
《人体寄生虫学》(詹希美教授主编)人民卫生出版社
(第二版)
Parasite online http://www.msu.edu/course/zol/316/
PARASITOLOGY online textbook:
http://pathmicro.med.sc.edu/book/parasit-sta.htm

http://202.116.102.10/BIOLOGY/news/home.aspx

http://pathmicro.med.sc.edu/book/parasit-sta.htm

Parasite online
http://www.msu.edu/course/zol/316/

http://www.cdc.gov/parasites/az/index.html

http://apps.who.int/tdr/

利用网上工具如Youtube搜寻视频学习资料

考试形式:100分
1、理论考试:
8年制及检验:笔试(期终):80分
2、实验考试:辩认虫卵或虫体标本(20个标本,15分)
实验课平时作业:5分)

Requirements
Specialized vocabulary: parasite name such as
Clonorchis sinensis ;
Important concepts: parasitism, parasite and host
Important stage of life cycle: infective stage and
pathological stage?
How to invade human body?
Which tissues or organs was/were parasitized?
Which stages can be detected as biomarker for
diagnosis?

1. 寄生虫学概述 Introduction of Parasitology
(parasites & hosts)
Lesson One
2. 吸虫概述 Trematodes
3. 华支睾吸虫 Clonorchis sinensis
4. 并殖吸虫 Pagragonimus westermani
姜片虫(Fasciolopsis buski)、肝片吸虫(fasciola hepatica)、
异形吸虫(Heterophyid trematodes)、
斯氏狸殖吸虫(Pagumogonimus skrjabini)

Biology of Parasites
• Symbiosis (共生现象)
• Parasitism (寄生现象)
• Parasite (寄生虫)
• Host (宿主/寄主)
• Life cycle
• Parasite-host interaction

Parasitism (寄生)
another type of symbiotic relationship between two
organisms: a parasite (寄生), usually the smaller of the two,
and a host (宿主), upon which the parasite is
physiologically dependent.
A parasite (寄生虫) : an organism that lives on or in a
host organism (宿主) and gets its food from or at the
expense of its host.
寄生物(parasite):
virus, bacterium, protozoa, helminths
one cell or multicellular organism

Survive Manner :
• Obligate parasite (专性寄生虫):
cannot survive in any other manner, such as most
human parasites
• Facultative parasite (兼性寄生虫):
exist in a free-living state or as a commensal state,
such as Strongyloides stercoralis
• Temporary parasite (偶然寄生虫):
somrtime invide into human (animal parasite)
Living in body or on the surface:
• Endoparasite (体内寄生虫)
• Ectoparasite (体外寄生虫)

There are three main classes of parasites that can cause
disease in humans, medical/human parasites:
1. Medical Protozoa(原虫)
2. Medical Helminths(蠕虫)
3. Ectoparasites/Medical arthropods(体外寄生虫或医
学节肢动物).
Helminths:
Trematode(吸虫)
Tapeworm/cestode (绦虫)
Nematode (线虫)

How to name parasite?
Phylum(门)、Class(纲)、Order(目)、
Family(科)、Genus(属)、Species(种)
Each parasite has two names: a
Genus(属名) and a Species name(种名)
Schistosoma japonicum
属名 种名

Medical Trematodes (吸虫)
1. Intestinal trematodes
Clonorchis sinensis (华支睾吸虫)
Fasciolopsis buski (布氏姜片虫)
Other interinal trematodes
2. Lung or other tissue trematodes
Pagragonimus westermani (卫氏并殖吸虫)
Pagumogonimus skrjabini (斯氏狸殖吸虫)
Human Schistosomes (人体血吸虫)

An example of a
adult trematode
morphological
structure
(os) oral sucker; (vi) vitellaria; (in) intestine;(vs) ventral
sucker.; (o) ovary; (ut) uterus; (ve) vas efferens; (t) testis;
(ab) excretory

Structure
1. Digestive system:mouth( oral sucker,
pharynx, esophagus) & intestine(ceca)
2.Reproductive system:
hermaphrodite(monoecism)/dimorphism
Male: testis, vas efferens, seminal vesicale,
cirrus,&cirrus pouch
Female: ovary, oviduct, ootype, Mehlis’ gland,
seminal receptacle, Laurer’s canal, vitellaria,
vitelline duct, & uterus

常见蠕虫虫卵(400×)
1.未受精蛔虫卵
2~4. 受精蛔虫卵
5~7. 钩虫卵 8. 鞭虫卵
9~10. 蛲虫卵
11~12. 带绦虫卵
13. 微小膜壳绦虫卵
14. 华支睾吸虫卵
15. 日本血吸虫卵
16. 肺吸虫卵
17. 姜片虫卵

Life cycle
Sexual generation
in definitive
host(有性生殖)
Asexual generation
in intermediate
host(无性生殖)

Adult worm(成虫), egg(虫卵), miracidium(毛
蚴), sporocyst(孢蚴), redia(雷蚴), cercariae(尾
蚴), metacercaria(囊蚴)

Part I
Clonorchis sinensis
华支睾吸虫(肝吸虫)

Which disease is correlated with Guangdong area?
?鼻咽癌(nasopharyngeal carcinoma )
? 肝吸虫病(Clonorchiasis)
?广州管圆线虫病 (Angiostrongyliasis)

food-borne parasitosis (食源性寄生虫病)
Public health problems
Most of parasitie trematodes are the agents of
the diseases:
Clonorchis sinensis (华支睾吸虫)
Fasciolopsis buski (布氏姜片虫)
Pagragonimus westermani (卫氏并殖吸虫)
Pagumogonimus skiabini (斯氏狸殖吸虫)

The Chinese liver fluke, the trematode
Clonorchis sinensis
found from the biliary passage of a
Chinese in Calcutta(加尔各答), India in
1874 firstly.
Clonorchiasis(华支睾吸虫病)

公元前167年 ancient corpse(湖北) 华支睾吸
虫虫卵与现代华支睾吸虫虫卵的序列比较

ITS1:96.7% (449/464)

Second national investigation:
调查 217,829人, 感染率 2.40%
最高 广东(16.42%)\ 其次 广西(9.76)
本次在流行区抽样调查感染率为2.40%。根据
本次调查和1992年完成的第一次人体寄生虫分
布调查相同抽样点调查结果统计分析,本次调
查华支睾吸虫平均感染率为0.58%,比第一次
调查的平均感染率0.312%,上升了85.90%。

1. Life cycle

Adult worm, egg,miracidium, sporocyst, redia,
cercariae, metacercaria
Adult worm
egg
Metacercaria
Cercariae
Miracidium-Sporocyst-Redia

In first /second intermediate host
Infective stage In definitive host

Alocinma longicornis
Parafossarulus striatulus

*终宿主:人或哺乳动物(保虫宿主)
成虫寄生在胆管内
*第一中间宿主:淡水螺
(纹沼螺、长角涵螺)
虫卵孵出毛蚴、胞蚴、雷蚴、尾蚴
*第二中间宿主:淡水鱼类
(麦穗鱼、草鱼、青鱼等) 囊蚴

How many stages of the life cycle?
Adult worm, egg, miracidium, sporocyst, redia,
cercariae, metacercaria
Which stage is infective stage? And how?
Metacercaria; eating (Ingestion )
Which stage inhabit humans? And where?
Worm; Bile duck
Which stage is primary cause of the disease?
worm
Which stage was detected for diagnosis?
Egg, worm

2. Morphology

Adult Worm

Younger worm
Sucker & spine

Mature egg
Size: 29 × 17 um
larger operculum,
shoulder
Small knob or curved
spine

华支睾吸虫囊蚴(Metacercaria)

3. Pathogenesis
Worm in bile ducts
Mechanical irritation Toxic substances
Proliferation in biliary
epithelium
Erosion of epithelium
Bile retention,
fibrosis,cancer

uterus

Histopathological findings of clonorchiasis (hematoxylin and eosin
stain). Note the flukes (arrows) within the dilated bile ducts, biliary
epithelial hyperplasia (arrowheads), and periductal fibrosis.

超声检查
Hepatic ultrasonography (right
intercostal oblique plane) in a
60-year-old woman (a) and a
41-year-old man (b) with
clonorchiasis. Note the diffuse,
uniform dilatation of the
intrahepatic bile ducts and the
increased echogenicity of the
ductal wall (arrowheads).
Flukes or aggregates of eggs
are shown as nonshadowing
echogenic foci within the bile
ducts (arrowheads in panel b).

Intrahepatic
peripheral
cholangiocarcinoma
in a 56-year-old
woman.
Transverse hepatic
CT shows a lowattenuation
mass (T)
in the right lobe of
the liver. Note the
dilated intrahepatic
ducts peripheral to
the tumor.

4. Clinical manifestation
After 1-3 weeks
fever,chills,
abdominal pain,
diarrhea
Tender hepatomegaly
mild jaundice(黄疸)
eosinophilia
SGOT, SGPT
Cholangitis(胆管炎)
Cholangiocarcinoma
(胆管上皮癌)
cirrhosis of liver

5. Diagnosis
(1) History of eating raw fish
(2) Stool examination
egg-concentration method
duodenal aspirate exam.
(3) Immunological tests: IHA/ELISA

华支睾吸虫的检查方法

6. Epidemiology
Definitive host: Human
Reservoir host:dogs,cats and rats
First and second intermediate host
Way of acquiring:eating raw fish with
metacerariae

7. Prevention and control
Health education and change of eating
habits
Praziquantel( 吡喹酮):
75 mg/kg, divided 3 doses one day
In Guangdong 150 mg/kg for 2 days
recommended

Summary
Life cycle:adult worm, egg, miracidium,
sporocyst, redia, cercariae, metacercaria
Definitive host: human(bile duct)
Reservoir host: dogs,cats and rats etc
First and second intermediate host:freshwater
snails and fish
Infective stage: metacercaria
Way to infection: eating/ Ingesting

The assembled genome has a total size of 516 Mb.
Approximately 16,000 reliable protein-coding
gene models were predicted

Part II Paragonimus westermani
卫氏并殖吸虫(肺吸虫)
50 species of paragonimus
P. westermani is the most important
In 1878, first description in tiger; in 1880,
first case found in Taiwan

Life cycle
adult worm(lung)
egg,
miracidium, sporocyst,
mother rediae and
daughter rediae,
cercariae,
metacercariae,
larvae (migranting)

1. After eating, larvae excyst in duodenum,
embed in abdominal wall or enter abdominal
cavity , penetrate diaphragm(膈) & pleura(胸膜),
enter the bronchioles of lungs。
2. In lungs, they encyst and mature to become
adult worm ( metacercariae egg >2 m) 。
3. Larvae may located in ectopic locations,
such as brain, mesentery, pleura or skin.

• Adult worm in lungs,
encyst, lay eggs.
• Cyst rupture, eggs
escape into the air
passage moving up &
out by ciliary epithelium,
arriving pharynx;
• Swallowed & passed
through digestive canal
to be voided with the
feces.

Morphology(形态学)
• Oral sucker &
ventral sucker same size
• ventral sucker at pre-equator
• cecum with two winding branches
• two lobated testes at same level
• ovary with 5-6 lobes at the left of midline
• uterus at the right of ventral sucker

10 vitelline cells
A germinal cell
operculum

Fresh water snail: 蜷科、黑贝科
Fresh water crayfish
Fresh water
crab

Pathogenesis
Pathological changes in host are caused by physical
trauma and chemical damages of flukes’ toxins.
1. Acute stage: invasion and migration of the young
flukes
2. Chronic stage:
abscess(脓肿期)、
granuloma(肉芽肿期)、
fibrous scar(纤维瘢痕期)

64 例肺吸虫病均有共同的病理学特点:肉眼
可见结节形成,镜下有坏死腔穴和窦道、
Charcot-Leyden 结晶及大量嗜酸性粒细胞浸
润,在坏死腔穴周围有肉芽组织包绕。

Pulmonary paragonimiasis(肺型)
Chronic cough, chest discomfort, bloodd sputum or
rusty-brown sputum
Young flukes(larvae) or adult worm also lodge
ectopic sites, e.g. liver, heart, subcutaneous tissue,
brain etc.
Extrapulmonary(肺外型)
• Cerebral paragonimiasis
• Liver paragonimiasis
• Cutaneous paragonimiasis
Larva migrating

Diagnosis
• History of eating raw
crustaceans(crabs )
• Parasitological examination :
sputum & feces
• Immunodiagnostic test:
IDT(intradermal test)
ELISA for special antibodies
dot-ELISA for Cag
• X-ray /CT examination of chest

Epidemiology
Three main foci:
Asia,
Africa
South & central America
In China, 23 provinces
Northern part of
China

Endemic areas Natural focus

• Definitive host: human/mammals
• Reservoir host: mammals
paratenic host/ transport host:
boar(wild pig)
• Natural focus(自然疫原地):
Parasitic zoonoses (人兽共患寄生虫病)
• The ways to acquiring infection: raw or
uncooked crab/crayfish, meat with immature
flukes

Reservoir host : The adult worm of helminths
or one stage of development of protozoa either
live in humans or in animals. Under some
condition, the parasite can infect humans from
infection animals, which animals are called
reservoir host. The parasitic disease is called
parasitic zoonoses
Natural endemic focus In some forest and
desert the parasitic zoonoses transmit among
vertebrate, which areas is called natural
endemic focus(自然疫源地)

Paratenic host or transport host (转续宿主)
The larva of some parasites can invade a
non-normal host, but can not develop, and
only keep the larva stage. If the larva enter a
normal definitive host, it can continue to
develop into adult worm. The non-normal
host is a called paratenic host or transport
host.

Reservoir host
some endemic: dogs
some endemic: wild animal

Prevention and control
Health education and change of eating habits
Use of molluscacides for snail control
Chemotherapy
Bithionol(硫双二氯酚)
Praziquantel:75mg/(kg.d) 2天

Could you pick up /find which
mistake in the report?

Fasciolopsis buski
布氏姜片吸虫
largest intestinal fluke , which can cause
Fasciolopsis
In 1873, first cases of Fasciolopsis was
found in Guangzhou

• Life cycle: adult worm, eggs, miracidium,
sporocyst, mother rediae, daughter rediae,
cercariae, metacercariae
• Definitive host: pigs & human
• inhabit organ: smail intestine
• Intermediate host: freshwater snail &
water vegetation
• infective stage: matacercaria

Conclusion
P. westermani C. sinesis F. buski
Definitive human human human
Reservoir host tiger, dog etc dog, cat etc pig
Paratenic host boar etc no no
Egg sputum/feces feces feces
Miracidium water snail water
Sporocyst snail snail snail
Rediae snail
mother snail snail
Daughter snail snail
Cercariae snail/water
Metacercariae crab/crayfish fish/shrimp water vegetation
Larvae migration no no
Adult worm lungs/other organs bile ducts intestine
Ectopic parasitism yes no no

Paragonimus westermani Clonorchis sinensis

Fasciola hepatica
肝片吸虫
A demostic animal’s parasite, and can
inhabit bile duck of human sometime

F.hepatica infection is found in rural areas
of temperate and tropical regions, related
to cattle herding.
High prevalence is described
in Europe and Latin America
as well as China.

F.hepatica infection is found in rural areas
of temperate and tropical regions, related
to cattle herding.
High prevalence is described in Europe and
Latin America as well as China.
Definitive host: demostic animals (bile duck)
Intermediate host: snail & water vegetation
infective stage: matacercaria

Study by yourself
Heterophyid trematodes (异形科吸虫)
Echinostomatidae (棘口吸虫)

Pagumogonimus skrjabini(Chen 1959)
Cutaneous paragonimiasis
Life cycle similar P. westermani
Definitive hosts: Paguma, cats, dogs etc
Human: non-normal host
Most of larvae cann’t develop to mature worm
Migration of larvae cause pathological changes
Immunological test & biopsy

P. skrjabini
斯氏狸殖吸虫
生活史与卫氏肺吸虫类似,多种动
物如:鼠类、蛙类及鸡等可作为转
续宿主;人为本虫的非正常宿主。
感染本虫引起皮下型并殖吸虫病,
属幼虫移行症,表现为皮下游走性
结节或包块,侵犯肺和肝也可造成
相应器官的病变,诊断应与肺炎、
肺结核及肝炎鉴别。

Conclusion
P. westermani C. sinesis F. buski
Definitive human human human
Reservoir host tiger, dog etc dog, cat etc pig
Paratenic host boar etc no no
Egg sputum/feces feces feces
Miracidium water snail water
Sporocyst snail snail snail
Rediae snail
mother snail snail
Daughter snail snail
Cercariae snail/water
Metacercariae crab/crayfish fish/shrimp water vegetation
Larvae migration no no
Adult worm lungs/other organs bile ducts intestine
Ectopic parasitism yes no no

Choi BI, Han JK, Hong ST, Lee KH.
Clonorchiasis and cholangiocarcinoma: etiologic
relationship and imaging diagnosis.
Clin Microbiol Rev. 2004 Jul;17(3):540-52
Rim HJ. Clonorchiasis: an update. J Helminthol.
2005 Sep;79(3):269-81.
Lun ZR, Gasser RB, Lai DH, Li AX, Zhu XQ,
Yu XB, Fang YY. Clonorchiasis: a key
foodborne zoonosis in China. Lancet Infect Dis.
2005 Jan;5(1):31-41.

Paragonimus westermani Clonorchis sinensis