(4)--人体寄生虫学考试试卷答案(英文)

Zhongshan School of Medicine, Sun Yat-sen University

Test Paper Type：ATest Time： 150 min　Test method：Closed-book testTest date：January 9, 2012 Answers[Part One] Choose the correct answer（1 score for each, and the total score is 40）

Type A: Choose the best answer from A, B, C, D and E.

1. Which tissue or organ is the common parasitic site of hydatid?

A. thoracic cavity B. lungs C. brain D. liver E. abdominal cavity2. Which stage of trichomonas vaginalis is infective stage?

A. trophozoite B. cyst C. mature cyst D. oocyst E. encysted larvae3. Which stage of plasmodium is the stage with pathogenicity?A. exo-erythrocytic stage B. erythrocytic stage C. gametocyte D. sporozoite E. oocyst

4. Which type of immune-response is associated with protozoal infection?

A. sterilizing immunity B. Non-acquired immunity C. premonition

D. concomitant immunity E. premonition and concomitant immunity5. For most parasitic diseases, what plays the role of sources of infection?

A. reservoir host B. patient and carrier C. paratenic host or transport hostD. intermediate host E. infected person and infected animal

6. If contacting soil with barefoots in the tea or vegetable garden, which parasite do you getinfection?

A. Clonorchis sinensis B. hookworm C. filaria D. Fasciola hepatica E. Trichnella spiralis 7. Which parasite is opportunistic parasite?

A. Entamoeba histolytica B. Plasmodium falciparum C. Toxoplasma gondiiD. Leishmania donovani E. Trichomonas vaginalis8. Which diseases are food-borne parasitosis?

A. schistosomiasis,clonorchiasis,ascariasis,angiostrogyliasis,taeniasis,toxoplasmosisB. ascariasis,hydatosis,trichinellosis,angiostrogyliasis,taeniasis,toxplasmosisC. clonorchiasis,trichinellosis,ascariasis,angiostrogyliasis,taeniasis,toxplasmosis

D. trichinellosis,paragonimiasis,chonorchiasis,angiostrogyliasis,taeniasis,toxplasmosis

E. pulmonary paragonimiasis,trichinellosis,angiostrogyliasis,hydatosis,taeniasis,toxplasmosis9. Which parasite can cause Keratitis?

A. Entamoeba coli B. Entamoeba histolytica C. Entamoeba disparD. Entamoeba gingivalia E. Acanthamoeba species

10.Which method can be used to diagnose kala-azar diseases or leishmaniasis?A. blood smear B. clinical manifestation C. stool examination

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D. bone marrow smear E. cell culture

11. Which mosquito can be control by reducing small or mini-fresh water- breeding grounds?A. Aedes albopictus B. Anopheles dirus C. Culex pipiens pallensD. Anopheles sinensis E. Culex pipiens quinquefasciatus

12. Which clinical manifestation was caused by Giardia lamblia infection?

A. bloody purulent stool B. acute or chronic diarrhoeaC. Fever D. anaemia E. jaundice

13. Which stage of Entamoeba histolytica is infective stage?A. cyst with two nucleus B. trophozoite C. oocyst D. amastigotes E. cyst with four nucleus

14. Which parasite can be examined by a strip of cellophane tape?A. eggs of schistosomes B. hookworm eggs C. pinworm eggs D. eggs of Ascaria lumbricoides E. whipworm eggs15. Which stage of plasmodium is the infective stage?

A. oocyst B. sporozoites C. gametocyte D. ring form E. zygote

16.Why does Taenia solium cause more serious harm than Taenia saginata ?A. Taenia saginata with less toxin

B. Taenia solium with small hooks and rostellum

C. more worms of Taenia solium parasitize in human beingD. cysticerci of Taenia solium can parasitize in human beingE. trauma of oncosphere

17. Which pathogenesis is major pathogenic effect caused by schistosoma eggs?A. blood vessels were blocked by eggs B. liver injury caused by eggs toxin

C. liver and intestinal tissues were compressed by eggs

D. hypersensitivity and egg-granuloma caused by the metabolic and exceretory products of eggsE. inflammation cause by egg antigens

18. Which epidemiological features are correlated to trichinellosis?

A. endemicity and group events B. endemicity, group events and food-borne infectionC. endemicity,and food-borne infection

D. group events and food-borne infection E. zoonoses

19. Which fresh water snail is the intermediate host of Angiostrongylus cantonensis?A. Alocinma longicornis(长角涵螺) B. Giant African snail(东风螺)

C. planorbid(扁卷螺) D. melania(川卷螺) E. Oncomelania hupensis(湖北钉螺)

20. Which parasite can be re-infected by contacting anus regions of patient and by hand-to-mouth transmission?

A. hydatidosis B. Ascariasis C. hookworm disease D. Trichuriasis E. Enterobiasis21．Which vector can transmit forest encephalitis?A. human flea B. lice C. bedbugs D. tick E. mite22. Which drug can be used to treat nematode infection?

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A. Albendazole B. Spiramycin C.penicillin

D. chloroquine E. Sulfamethoxazolum-Trimethoprimum (SMZ-TMP)

Type B: Choose the correct answer from A, B, C, D and E to the square bracket of each item.Question 23~26

What damages were caused by the following parasites?

A. Entamoeba histolyticaB. Echinococcus granulosusC. Plasmodium falciparumD. Ascaris lumbricoidesE. Schistosoma japonicum 23. to cause intestinal obstruction（ ）24. to cause serious anemia（ ）25. to cause liver cirrhosis（ ）26. to cause liver abscess（ ）

Question 27~30

Which parasite can be infected by eating the following raw food?A. fresh water fish B. beef C. frog D. water plants E. crabs27. Spirometra mansoni（ ）28. Paragonimus westermani（ ）29. Fasciolopsis buski（ ）30. Taenia saginata（ ）

Type X: Choose the correct answer from A, B, C, D and E, and the correct answer may be notjust one.

31. Which parasite(s) can cause splenomegaly?

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A. plasmodium B. Entamoeba histolytica C. schistosoma japonicumD. Strongyloides spp E. Leishmania donovani32. Which stage of protozoa can infect human being?

A. trophozoite of Toxoplasma gondii B. trophozoite of Entamoeba histolyticaC. trophozoite of Trichomonas vaginalis D. trophozoite of Giardia lambliaE. oocyst of Cryspordium

33. Which mite or insect can parasitize in human body for longer time? A. scab mite B.mosquito C. cockroach D. lice E. trombiculid mite34. Which disease(s) can be transmitted by medical arthropods?A. filariasis B. pulmonary paragonimiasis C. malariaD. Kala-azar disease E. trichinellosis

35. Which damages to human being are caused by parasites?

A. loss nutrition B. Direct damage such as trauma C. inapparent infectionD. toxin and inflammation E. polyparasitism36. Which parasite(s) can cause visceral larva migrans?

A. Gnathostama spinigerum B. Pagumogonimus skrjabini C. AnisakisD. Spirometra mansoni E. Angiostrongylus cantonensis37. Which parasite(s) can parasitize in brain?

A. Angiostrongylus cantonensis B. Spirometra mansoni C. Taenia soliumD. Fasciolopsis buski E. Fasciola hepatica38. Which vectors can transmit malaria in China?

A. Anopheles sinensis B, Anopheles anthrophagus C. Anopheles minimusD. Culex pipiens pallens E. Anopheles dirus

39. Which direct damages are caused by medical arthropods?A. toxicosis

B. harassment and sucking bloodC. sucking blood and transmitting diseasesD. invading tissueE. allergy

40. Which stage of parasite can be detected by stool examination?A. eggs of Ascaris lumbricoidesB. eggs of Schistosoma japonicum

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C. hookworm rhabditoid larvaD. whipworm eggs E. eggs of Fasciolopsis buski

[Part Two] Item interpretation

（3 scores for each, and the total score is 12）

1. immunoevasion of parasite

Parasites survive and proliferate in immunologically competent host by intracellular location, antigenic shedding, antigenic variation, antigenic mimicry, and modification of host immune responses.

2. paratenic host or transport host

The larva of some parasites can invade a non-normal host, but cannot grow, and only lives in the larva stage. If the larva enters a normal definitive host, it can continue to grow into an adult

worm. The non-normal host is called paratenic host or transport host. It functions as a transport orcarrier host.

3. complete metamorphosis

From eclosin of larva or nymph to adult, there are wide differences in the morphology,

physiological function and living habits. The process of the change is called metamorphosis. The complete metamorphosis includes egg, larva, pupa and adult. 4. relapse of malaria

There are no malaria parasites in red blood cells after antimalarial drug treatment. However

malaria is back into the disease weeks, months or even years after the apparent cure without new infection. It caused by hypanzoites develop into schizonts in liver cells. Only P. vivax and P. ovale of humans cause relapse.

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[Part Three] Answer the question briefly（5 scores for each, and the total score is 10）

1.In laboratory, how to make mouse infect plasmodium parasite? And how to prove the mouse has been infected？

Answer:

Obtain 2 drops of blood from P. berghei infected mouse tail, diluted in 2-ml saline solution; inject 0.1-ml diluted blood to a mouse abdominal cavity.

After one week, collect blood from parasite infected mouse tail to make thin and thick blood films. Fix the film with methyl alcohol and stain with Giemsa’s solution, and then exam the slide to find malaria parasites under immersion oil microscope.

2. Which diseases can be transmitted by mosquito? Please describe the mechanism of disease-transmission.

Answer:

The following diseases can be transmitted by mosquito: Malaria, Filariasis, Japanese B encephalitis, Dengue fever (or yellow fever).Malaria: development and proliferationFilariasis: development

Japanese B encephalitis: proliferation (or transmission by egg)Dengue fever: proliferation (or transmission by egg)

[Part Four] Answer the questions. (The total score is 38)

1. Schistosomiasis is still an important public health problem in China, please tell me how to control the disease. (10 scores)

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Answer:

There are different methods used in different endemic areas. A.Elimination of the infective resources:

a.Selective chemotherapy for human, chemotherapy for livestoke;b.Medicine, Praziquantel ;B.Cut off the transmision route:

a.Snail control; intermieate host Oncomelania hupensis;

b.Feces management: including human and livestock’s stool; kill the eggs;c.Safe water supply:

C.Protecting susseptibel individual:

a.Health education; to know the life cycle of Schistosoma japonicum.

d.Individual prevention: taking artemisinin; avoiding contact with infected water.2. If you drank un-boiling water, which parasites will you infect? Which stages ofthose parasites are infective stage? Please describe the pathogenesis and harms onhuman by using two parasites as examples. (13 scores)Answer:

Parasites from drinking un-boiled water:1)Entamoeba histolytica, four-nuclei cyst;2)Giardia lamblia, four-nuclei cyst;3)Cryptosporidium, oocyst;

4)Trichuris trichiura, egg; Enterobius vermicularis, egg, etc.

Examples:

1)Pathogenesis of Entamoeba histolytica:

A.The amoebae secrate proteolytic enzymes to hydrolyse host. B.Slender duct like ulcer in the lumen of intestine;C.Intestinal amebiasis and extraintestinal amebiasis.2)Pathogenesis of Giardia lamblia:

A.Mechanical blochage of the intestinal mucosa, competition for nutrients, inflammtion of theintestinal mucosa, etc.B.Shortening of microvilli;

C.Diarrhea, abdominal pain, nausea and vomitting;D.Commonly infected immuno-suppressed persons.3. Clinical case analysis (15 scores)

A previously healthy 26-yr-old male was referred to our hospital because of recently recognizedjaundice. He complained of anorexia, fatigue, and weight loss of 8 kg over the previous eightmonths. He lives in the suburbs of Guangzhou. The medical history was unremarkable except foringestion of raw freshwater fish. The patient had a blood pressure of 124/81 mmHg, a heart rate of80 beats/min, a respiration rate of 15 breaths/min, and a body temperature of 36.7℃. The physical

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examination was unremarkable except for generalized jaundice. The laboratory data revealed whiteblood cell count 7,100/µL (normal range 4,000-10,000/µL) with 18.3% eosinophils (0-4%),hemoglobin level 12.4 g/dL (13-17 g/dL),etc. Serologic testing of viral markers showed HBs Ag (-),antiHBs Ab (+), antiHAV IgM (-), and HCV Ab (-). The abdominal CT scan showed mild dilatationof the intrahepatic bile ducts.Questions:

① Which parasitic infection did the patient suffer from? Why?② Why did the patient present with painless jaundice? ③ Which examination will you suggest for the patient?④ Which drug can treat the patient?

⑤ Which parasite(s) can cause the pathological changes in liver?

答：（1）该病人可能感染了华支睾吸虫（肝吸虫）（3分）

原因：a.该患者曾吃过生鱼片，有生鱼片中可能寄生有华支睾吸虫的感染期囊蚴;（1

分）

b腹部CT扫描显示肝内胆管中度扩张; （0.5分）c. 出现黄疸（0.5分）

（2）华支睾吸虫成虫寄生在肝内胆管，机械刺激、代谢产物和分泌物等引起胆管内膜及胆

管周围的炎性反应，最后导致胆管上皮腺瘤样增生。(1分)

由于胆管壁增厚，管腔相对狭窄和虫体堵塞胆管，可出现阻塞性黄疸（无痛性黄

疸）。（1分） (3) 该病人还应该做的检查

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a.病原学检查 取粪便（或十二指肠引流液）查虫卵。（2分）

b.血清学检查 查特异性抗体或循环抗原（1分）

(4) 该病人应采用的治疗药物为吡喹酮（或阿苯达唑）（2分）

(5)可引起肝脏病变的寄生虫主要有：华支睾吸虫、日本血吸虫、溶组织内阿米巴、细

粒棘球绦虫、并殖吸虫、肝片形吸虫、曼氏迭宫绦虫（裂头蚴）、疟原虫、猪带绦虫

（嚢尾蚴）、蛔虫、杜氏利什曼原虫、弓形虫等。（要求答6个虫，前4个为必答，后

面的可选2个答。每个虫0.5分，共3分）

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