Cairo University
Date --/--/2013
Time allowed: 1hour
Faculty of Medicine
Answer of Mid–year Exam (trial)
Parasitology
The examination includes the following : (Total:8pages, total 20 marks)
QI : MCQs (20MCQs)
(5marks)
QII : 3 Cases
(9 marks)
QIII: Give reason
(3marks)
QIV: True and False question
(3 marks)
All the questions should be answered in this sheet
Question I M.C.Q.s
1-Infection with Trichostrongylus occurs through:
a-Ingestion of embryonated eggs
b-Ingestion of rhabditiform larvae
c-Ingestion of filariform larvae
d-Penetration of skin by filariform larvae
2- Anaemia of Diphyllobothrium latum is due to:
a-iron deficiency
b-bone marrow depression
c- vit. B12 deficiency
d- blood loss
3- The commonest helminthic infection in children is
a- Enterobius
b- Fasciola
c- Taenia saginata
d- Heterophyes
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4 -Ingestion of eggs of Multiceps results in:
a- cysticercosis
b- coenurus cyst
c- hydatid cyst
d- sparganosis
5- Callabar swelling of Loa loa
a- is usually found in the eyes
b- causes blindness
c- is transient
d- contains adults and microfilariae
6-The pathogenecity of Wuchereria is due to:
a- circulating microfilariae
b- death of microfilaria
c- adults worms in lymph vessels
d- nocturnal periodicity
7-Dysentery is a manifestation of:
a- Ascariasis
c- Trichuriasis
b- Fascioliasis
d- Enterobiasis
8- Visceral larva migrans occurs by:
a- Ingestion of larva of non-human nematodes
b- Penetration of the skin by larva of Ancylostoma of dogs
c- Penetration of the skin by larva of Ascaris of dogs
d- Ingestion of food containing eggs of non-human nematodes
9- The following infection is geohelminthic
a- Fascioliasis
b- Paragonimiasis
c -Ascariasis
d- Giardiasis
10-Chyluria is more common in:
a-Urinary schistosomiasis
b-Wuchereria bancrofti elephantiasis
c-Brugia malayi elephantiasis
d-Enterobius infection of male patients
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11- In Echinococcus granulosus man act as:
a- definitive host
b- reservoir host
c- intermediate host
d- paratenic host
12-Man is infected with fascioliasis by eating contaminated:
a- raw liver
b- raw meat
c- raw fish
d- raw vegetables
13- Cysticercosis result from ingestion of
a- eggs of Taenia saginata
b- eggs of Taenia solium
c- cysticercus cellulosae
d- cysticercus bovis
14- Opportunistic parasite :
a- lives outside the body
b- lives inside the body
c- produce disease in immunodeficient patients only
d- has free or parasitic existence
15- The snail intermediate host of Heterophyes is:
a- Lymnaea cailliaudi
b- Lymnaea truncatula
c- Semisulcospira
d- Pirenella conica
16- Man is infected with Dracuculus medinensis by:
a- walking bare footed
b- coming in contact with water containing cyclops
c- drinking water containing cyclops
d- auto-infection
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17-Halzoun:
a-is caused by linguatula serrata only
b-is caused by Fasciola hepatica metacercaria
c-is caused by eating raw liver of sheep and goat
d-is prevented by proper washing of vegetables
18-The microfilariae of Wuchereria bancrofti inside the vector:
a- increase in number
b-increase in size
c- increase in number and size
d- remain unchanged
19- Appendicitis may be caused by the following parasitic infection:
a-Heterophyiasis
b-Hymenolepiasis
c-Ancylostomiasis
d-Taeniasis
20-Parasitism is permanent association between 2organisms in which
a- both benefit
b- one partner benefits and the other is unaffected
c- one partner benefits and the other is harmed
d- none of the above
QuestionII (Cases)
Case I (4marks)
A child aged 12 years old from fayoum complained from weakness,
dyspnea, tachycardia and palpitations ,oedema of lower limbs. There is
severe anaemia Stool analysis reveals the following egg
a –What is your provisional diagnosis?
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Ancylostomiasis………..
(1Mark)
b- How the patient gets infected and what is the infective stage?
By walking bare footed (1/2mark)
The infective stage is filariform larva (1/2mark)
c- What is the cause of anaemia?
Haemorrhage due to the attachment of the parasite to the mucus membrane
by its cutting teeth (1/2m)
Each parasite causes loss of 0.3cc blood /day due to sucking of blood and
bleeding at site of attachment (1/2m)
d-How to prevent such disease
1-mass treatment 2-health education :avoid defaecation on the ground
and avoid walking bare footed 3-wearing shoes and gloves 4-disinfection of
human excreta used as fertilizers
(1mark)
Case II (3marks)
A female aged 35 years old complained of sudden fracture of the leg. The X
ray reveals the lesion shown in the figure
a-what is your provisional diagnosis
(1/2 mark)
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hydatid cyst in the bone
b- How man gets infected
(1/2mark)
by eating food contaminated with Echinococcus granulosus eggs.
c- Mention 2other sites of such infection
(1mark)
liver, lung, brain ,kidney.(any 2 sites are correct)
d- Mention 2 other methods of diagnosis of this parasitic infection
1-serological test (IHA)
2-molecular diagnosis
3-intradermal test casoni test
4-ultrasonography
5-detection of hydatid material (any 2 methods are correct)
Case III ( 2 marks)
A farmer aged 45 years complained of oedema of lower limbs and distension
of the abdomen. On clinical examination there was pulmonary hypertension.
He gives history of passing mucus and blood in stool many years ago
a -What is your suspected diagnosis
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Bilharzial cor pulmonale (1/2mark)
b-Explain the cause of pulmonary hypertension
Eggs which fail to be fixed to walls of the venules are swept to pulmonary
arterioles leading to granulomas formation . this will cause obliteration of
the blood flow causing pulmonary hypertension (1.5m)
Question III (3 marks)
Give reason for:
1-Persistent of infection with strongyloidiasis
Due to autoinfection
a-internal autoinfection :in patient with constipation rhabditiform larva
transform into filariform larva which penetrate the mucosa of large intestine
b-external autoinfection :some filariform larva can penetrate the perianal
skin after coming from the anus
(1mark)
2-Well water must be filtered before consumption
Because well water may contain infective cyclops so water must be filtered
to prevent infection with dracunculiasis or sparganosis
(1mark)
3-The invalidity of stool examination in suspected cases of fascioliasis
*Because it is only positive 3-4 months after infection
*Eggs are not detectable in chronic infection (due to fibrosis
*Spurious infection when eggs are detected in the stool after ingestion of
liver from infected animal
(1mark)
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Question IV (3marks)
Mark True (T) or False (F) and correct the false statement
1-Man is infected by Heterophyes by eating unwashed green salad (…F..)
Man is infected by Fasciola by eating unwashed green salad OR
Man is infected by Heterophyes by eating undercooked fish (bolti or bouri)
2- Microfilaria of Brugia malayi shows diurnal periodicity
(…F….)
Microfilaria of Loa loa shows diurnal periodicity OR
Microfilaria of Brugia malayi shows nocturnal periodicity
3-Trichinella spiralis could be complicated by rectal prolapse
Trichuris trichura could be complicated by rectal prolapse
Best wishes
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( F…)