FREDRICK PAUL fredrickpau88@fredrick.com
SECOND BATCH PARASITOLOGY MCQ. 0786236417
ANSWERS ON END OF THE DOCUMENT
15. Cerebral malaria
A) is associated with P.vivax infection
B) is caused by P. falciparum infected RBC plugging the cerebral microvasculature
C) is caused only by chloroquine resistant Plasmodium strains
D) could occur during a relapse of malaria 40 years after initial infection
with the parasite
E) is a psychiatric disease associated with delusions of parasitosis
16. Babesiosis
A) can cause severe anemia in splenectomized patients;
B) replicates within erythrocytes similar to malaria parasites
C) is endemic in the US
D) is transmitted by tick insect vectors
E) all of the above are true
17. Leishmania parasites
A) can infect any nucleated mammalian cell
B) replicate intracellularly within the endosomal compartment of the cell
C) are transmitted by the blackfly insect vector
D) cause massive dilatation of segments of the gastrointestinal tract
during chronic infection
E) are sexually transmitted parasites
23. Chagas disease
A) is also known as african trypanosomiasis
B) causes an encephalitis commonly called sleeping sickness
C) is transmitted by tsetse flies
D) causes cardiac and gastrointestinal pathology during chronic infection
E) is exclusively an extracellular protozoan pathogen
24. Protozoa and metazoa share all of the following characteristics EXCEPT:
A) infections with these parasites frequently cause eosinophilia;
B) can be transmitted orally, percutaneously or through insect vectors;
C) can involve complex life cycles requiring maturation in both humans
and other species;
D) disease is commonly caused by immune mediated mechanisms induced by
chronic infection;
E) cause chronic infections that remain asymptomatic in many infected patients.
Match the following helminthic parasites with the most appropriate statements
in questions 49-53:
A) Strongyloides stercoralis
B) Onchocerca volvulus
C) Schistosoma japonicum
D) Taenia solium
E) Ascaris lumbricoides
49. Infection with the eggs of this parasite is the most common cause of
new onset seizures in Mexican adults.
50. This parasite is known as the "giant roundworm" and can cause
intestinal obstruction.
51. Autoinfection with this parasite in immunocompromised individuals can lead
to fatal hyperinfection.
52. Infection with this parasite can lead to seizures due to egg deposition in the CNS.
53. This parasite is a common cause of blindness in Africa.
57. The mold recovered from the patient MOST LIKELY belongs to the genus
A) Mucor
B) Aspergillus
C) Cryptococcus
D) Rhizopus
E) Histoplasma
65. Each of the following statements regarding Coccidioides immitis is correct EXCEPT:
A) It is a dimorphic fungus that grows as a mold in the soil and as spherules
in the body
B) Infection usually results from the inhalation of asexual spores (arthroconidia);
hence, the primary site of infection in the lung
C) When cultured in the laboratory, the organism forms budding yeasts
D) The most important host defense against this organism is
cell-mediated immunity
Section 2
6. All of the following are characteristic of Blastomycosis EXCEPT:
A) pulmonary involvement can lead to pneumonia, weight loss, and bloody sputum
B) skin involvement seen as crusted or ulcerated lesions
C) habitat in decaying vegetation
D) large broad based yeast cells seen in tissue
E) when inhaled, spores develop into large spherules containing endospores.
28. All of the following are dimorphic fungi EXCEPT:
A) Blastomyces dermatitidis
B) Cryptococcus neoformans
C) Coccidioides immitis
D) Histoplasma capsulatum
33. Each of the following is characteristic of histoplasmosis EXCEPT:
A) transmission by inhalation of spores
B) granulomatous lesions in the lungs
C) endemic in the southwest sonoran belt
D) skin tests are positive for life
E) reticuloendothelial involvement predominates in disseminated disease
37. A patient with respiratory problems yields a sputum specimen
containing yeast cells. A latex agglutination test for
antigen is positive, as is an India ink test for capsules,
and the germ tube test is negative. Which organism is MOST likely?
A) Candida albicans
B) Coccidioides immitis
C) Cryptococcus neoformans
D) Aspergillus flavus
E) Blastomyces dermatitidis
50. A patient with chronic leukemia presents with a rapidly
advancing infection of the nasal sinuses. Biopsy and stain
of the specimen with calciflor white showed fragments of
non-septated hyphae and a sac-like structure apparently
containing spores. The MOST likely organisms is:
A) Candida
B) Mucor
C) Aspergillus
D) Coccidioides
E) Cryptococcus
51. Candida albicans is usually a relatively harmless commensal
parasite. Which of the following contributes LEAST to the
ability of the organism to cause infection?
A) Decreased immune defenses
B) Increased mannan-binding to fibronectin and collagen
C) Production of mycotoxins by yeast cells in tissue
D) Increased use of antibiotics
E) Production of proteinase by hyphae in tissue
52. Which of the following anti-fungal agents works via an affinity to sterols
in the organism, which then causes a perturbation of the cell membrane?
A) Griseofulvin
B) 5-fluorocytosine
C) Miconazole
D) Ketoconazole
E) Amphotericin B
53. A patient from the central U.S. who had a previous bout with
tuberculosis, now presents with pulmonary problems. Nodular
lung lesions are seen on chest X-ray, and a CBC indicates
neutropenia. Hyphal elements were observed directly in a
sputum specimen. Which is the MOST likely diagnosis?
A) histoplasmosis
B) coccidioidomycosis
C) cryptococcosis
D) aspergillosis
E) blastomycosis
Section 3
1. A diabetic patient presented with a necrotic lung infection. Biopsy specimens
revealed organisms with non-septate hyphae and subsequent culture grew
colonies with sporangiospores formed within a sac on a long stalk.
The MOST LIKELY infecting organism is
A) Cryptococcus
B) Sporothrix
C) Mucor
D) Aspergillus
E) Coccidioides
32. Which of the following is LEAST associated with Candida albicans infection?
A) Pseudohyphae observed in tissue biopsy
B) Germ tube formation
C) Proteinase production in vivo
D) Yeast forms grown in culture
E) Penetration of blood vessels in vivo
33. Factors contributing to the initiation of fungal infections include
each of the following EXCEPT:
A) Use of antibiotics
B) Anaerobic wound conditions
C) Neutropenia
D) Indwelling catheters
E) Defective cell-mediated immunity
Items 45-49 (Use each choice A-E only once)
A) Histoplasmosis
B) Blastomycosis
C) Coccidioidomycosis
D) Paracoccidioidomycosis
E) Cryptococcosis
For each patient presentation below, select the MOST LIKELY
diagnosis (A-E)
45. Chronic cough, worsening shortness of breath, 8 kg. weight
loss and night sweats in a farmer with emphysema, first
noted after building an addition to his barn 4 months ago.
46. Weight loss and malaise, cough, ulceration in the mouth, and
crusting lesion on the face of a Peace Corps volunteer who
assists in clearing land in Venezuela.
47. Headache and low-grade fever for 10 days, now brought in
with confusion and stiff neck. Known to be HIV-infected.
48. Fever, cough, painful red lumps on legs, and new onset right
knee arthritis in a pregnant woman recently transferred to
Phoenix.
49. Enlarging skin ulcerations on arms and buttock over the past
month, beginning 2 weeks after camping in Wisconsin; dog
also ill.
18. Infection by a dermatophyte is MOST often associated with
A) intravenous drug abuse
B) fecal-oral route of transmission
C) adherence of the organism to perspiration-moist skin
D) inhalation of the organism from contaminated bird feces
19. A non-dimorphic fungus found in concentrated bird droppings
and which readily causes meningitis in compromised individuals:
A) Coccidioides immitis
B) Paracoccidioides brasiliensis
C) Cryptococcus neoformans
D) Aspergillus fumigatus
E) Sporothrix schenckii
21. Three weeks after Traci Rappaport traveled to California to study desert
flowers during Spring break, she developed fever, chest pain, and
muscle soreness. Two days later, red, tender nodules appeared on her
shins, and she had pain and tenderness in the right ankle. An X-ray film of the
chest showed a left pleural effusion. The MOST LIKELY diagnosis is:
A) blastomycosis
B) coccidioidomycosis
C) histoplasmosis
D) Mycobacteria infection
E) Mycoplasma infection
23. A vaccine MOST LIKELY to be effective against fungal infection should:
A) produce antibodies to fungal exotoxins.
B) induce a strong thymic-independent IgM response to fungal antigens.
C) favor the stimulation of Th2 helper cells.
D) include vectors or adjuvants designed to encourage endogenous
pathways of antigen processing.
E) induce the production of gamma interferon.
31. Which of the following is an anti-mycotic agent which inhibits ergosterol
biosynthesis in fungi and which can be used for topical or systemic infection?
A) Amphotericin B
B) Griseofulvin
C) Nystatin
D) Ketoconazole
E) Pentamidine
59. Which is the LEAST accurate observation concerning Candidal infections?
A) pseudohyphae are seen in infected tissue.
B) germ tube formation occurs in serum at 37 C.
C) positive DTH skin test is diagnostic for disseminated disease.
D) budding yeast cells are seen in infected tissue specimens.
E) fungal cells attach to specific epithelial receptors.
60. Which of the following concerning the pathogenesis of fungal infections is LEAST correct?
A) Transmission of organisms by inhalation or penetration is common.
B) Iron-binding serum transferrin inhibits the growth of fungi in vivo.
C) Damage may be due to invasion of tissue and displacement of
normal cellular architecture.
D) Damage frequently is due to granulomatous inflammation.
E) Neutrophils as opposed to lymphocytes, play
little role in protection from fungal infection.
64. Characteristics of Histoplasma capsulatum include all EXCEPT:
A) It is a dimorphic fungus existing as a yeast in tissue.
B) It is found in soil heavily contaminated by bird droppings.
C) It is endemic in the Ohio and Mississippi River valleys.
D) Severe disseminated histoplasmosis occurs even in immunocompetent
hosts because of the survival of the organism within macrophages.
E) Lung pathology is primarily seen as a granulomatous response
to the organism.
79. Aspergillus fumigatus can be involved in a variety of clinical conditions.
Which of the following is LEAST likely to occur?
A) Colonization of tuberculous cavities in the lung.
B) Tissue invasion in immunocompromised patients.
C) Allergy following inhalation of airborne particles of the fungus.
D) Erythema nodosum or erythema multiforme.
Section 4
9. A middle aged transplant patient under immunosuppressive therapy is
nonetheless undergoing a rejection episode. He presents with fever
and with pain and necrotic skin near the left eye. Biopsy of the lesion
shows non-septate hyphae invading the blood vessels. Which is the
MOST LIKELY cause:
A) Aspergillus species
B) Mucor species
C) Candida species
D) Cryptococcus neoformans
E) Histoplasma capsulatum
10. Each of the following statements concerning Blastomyces dermatitidis
is correct EXCEPT:
A) the organism is a dimorphic fungus that forms yeasts with
broad-based buds in tissue
B) the organism cause granulomatous skin lesions
C) the organism is transmitted by inhalation
D) the organism grows as a mold in the soil in North America
E) infection by the organism is commonly diagnosed by rising antibody titer
12. A vaccine MOST LIKELY to be effective against Histoplasma capsulatum
infection should:
A) produce blocking IgG antibodies to fungal mycotoxins.
B) induce a strong T-independent response to fungal antigens.
C) increase the stimulation of Th2 helper cells.
D) induce the production Il-12 and Th1 helper cells.
E) decrease the expression of Class II MHC determinants
recognized by CD4+ cells.
37. A young woman pricked her finger while pruning rose bushes and subsequently
develops a localized pustule progressing to an ulcerative lesion. Several nodules
develop along the local lymphatic drainage of the site of injury.
The MOST LIKELY agent is
A) Candida albicans
B) Aspergillus fumigatus
C) Cryptococcus neoformans
D) Sporothrix schenkii
E) Blastomyces dermatitidis
74. Which of the following conditions is LEAST LIKELY to occur as a result of
Aspergillus fumigatus infection?
A) thrush
B) granulomatous infection of the lung
C) tissue invasion in immunocompromised hosts
D) colonization of tuberculous cavities in the lung
E) allergic reaction to inhaled fungal particles
61. Each of the following statements concerning Giardia lamblia is correct EXCEPT:
A) It has both a trophozoite and a cyst stage in its life cycle.
B) It can be diagnosed by the string test.
C) It is transmitted by the fecal-oral route from both human and animal sources.
D) It causes hemolytic anemia.
E) It causes diarrhea
97. A cestode (tapeworm) that is acquired by eating undercooked pork:
A) Strongyloides stercoralis
B) Paragonimus westermani
C) Taenia solium
D) Plasmodium falciparum
E) Entamoeba histolytica
98. The anatomic location of inflammation caused by Schistosoma mansoni is primarily:
A) the bone marrow
B) renal tubules
C) intestinal venules
D) lung alveoli
Section 5
1. All of the following would suggest the diagnosis of a malaria infection with
Plasmodium falciparum and not Plasmodium vivax EXCEPT:
A) the absence of schizont forms of the parasite in giemsa stained bloodsmears
B) presence of multiple ring-form trophozoites infecting a single erythrocyte
C) clinical manifestations of severe, rapidly fulminant anemia and
cerebral malaria
D) the presence of banana-shaped gametocytes in giemsa stained bloodsmears
E) relapse of clinical malaria up to 40 years after the last travel to an
endemic region
2. Babesiosis:
A) is transmitted by mosquitoes
B) can be treated with chloroquine
C) is associated with parasite replication in erythrocytes
D) can cause severe anemia in non-splenectomized individuals
E) all of the above are correct
3. All of the following are true of Leishmaniasis EXCEPT:
A) associated with cutaneous, mucocutaneous and visceral forms of disease
B) transmitted by sandfly vectors
C) organism is able to infect mammalian macrophages
D) recurrent parasitemia is due to high antigenic variation of the organism
4. All of the following are common causes of opportunistic infections in
AIDS patients EXCEPT:
A) Toxoplasma gondii
B) Entamoeba histolytica
C) Pneumocystis carinii
D) Candida albicans
5. Strongyloides stercoralis:
A) is transmitted percutaneously;
B) is coughed up and swallowed prior to development into the adult form
C) is associated with severe hyperinfection in immunosuppressed individuals
D) can be associated with eosinophilic pneumonia
E) all of the above are correct
7. Which of the following statements concerning Schistosoma mansoni is
NOT CORRECT?
A) it is transmitted percutaneously
B) adults live within venous plexi that supply the bladder
C) chronic infection is associated with portal hypertension
and esophageal varices
D) it is a Trematode (fluke)
8. Which statement concerning Neurocysticercosis is NOT CORRECT?
A) occurs in individuals after the ingestion of infected pork
B) is caused by larval forms of Taenia solium that induce
inflammation in the brain
C) is a common cause for seizures presenting in adulthood in
individuals who grew up in rural Mexico
D) is caused by a tapeworm
9. Ascaris lumbricoides:
A) is known as the giant roundworm
B) is acquired through ingestion of eggs in contaminated soil
C) can cause acute intestinal obstruction
D) all the above are correct
10. Paragonimus westermani:
A) is known as the oriental liver fluke
B) can be diagnosed by detection of parasite eggs in sputum samples;
C) is associated with endstage liver cirrhosis
D) is associated with brain abscesses
E) is transmitted by the anapheline mosquito
Use the following for Questions 49 - 50 :
A) Entamoeba histolytica
B) Plasmodium falciparum
C) Taenia solium
D) Paragonimus westermani
E) Strongyloides stercoralis
49. A nematode (roundworm) that is acquired when filariform larvae penetrate the skin.
50. Laboratory diagnosis is based on finding eggs in the sputum
For Question 56: Three U.S. oil prospectors assisted in the surveying
a potentially productive oil field in the jungles of Brazil. One month
after returning to the U.S., two of the men developed lesions on their faces,
arms and necks which progressively increased in size and began to ulcerate.
The men also experienced mild fever, weight loss and reduced appetites.
A Giemsa stain of pus taken from the lesions showed white cells and
macrophages. Some cells were degenerate with vacuolated cytoplasm
containing numerous, 1-2 þm structures with darkly stained nucleoids.
56. The history of the individuals and description of the intracytoplasmic
structures observed in infected white cells are consistent
with a preliminary diagnosis of
A) malaria
B) schistosomiasis
C) leishmaniasis
D) giardiasis
E) sleeping sickness
Section 6
3. Babesiosis is similar to malaria in which of the following ways?
A) transmission by mosquitoes
B) susceptibility to chloroquine
C) replication of the parasite in erythrocytes
D) ability to cause severe anemia in non-splenectomized individuals
4. Chagas disease
A) is also known as african trypanosomiasis
B) causes an encephalitis commonly called sleeping sickness
C) is transmitted by tsetse flies
D) causes cardiac and gastrointestinal pathology during chronic infection
E) is exclusively an extracellular protozoan pathogen
5. Helminthic infections:
A) are caused by single-celled organisms
B) are predominantly intracellular infections
C) are sometimes associated with eosinophilia
D) always require an insect vector for transmission
E) are caused by organisms which replicate by binary fission
6. Which are characteristics of Echinococcus granulosus?
A) infections cause expanding space occupying lesions within the liver
B) it is a tapeworm
C) rupture of a cyst caused by this organism can cause life-threatening
anaphylaxis
D) All of the above are correct.
34. All of the following are associated with Plasmodium falciparum infections EXCEPT:
A) stained bloodsmears rarely contain identifiable schizont forms of the parasite.
B) all ages of erythrocytes can be infected.
C) severe, rapidly fulminant anemia and cerebral malaria are common clinical
manifestations.
D) double ring form trophozoites and banana-shaped gametocytes are diagnostic
of infection with this species of plasmodia.
E) relapses can occur up to 40 years after the initial infection.
35. The following statements concerning Schistosomiasis are correct EXCEPT:
A) Most infections are asymptomatic
B) infections with Schistosoma mansoni can cause liver damage which results
in portal hypertension and bleeding esophageal varices
C) infections with Schistosoma haematobium can result in bladder inflammation
predisposing to urinary tract infections and bladder carcinoma
D) ova found in feces with a prominent lateral spine are diagnostic of infection
with Schistosoma japonicum
E) all schistosomes require snails as intermediate hosts
Use each choice (A-E) only once for Questions 50-54
A) Strongyloides stercoralis
B) Onchocerca volvulus
C) Schistosoma japonicum
D) Taenia solium
E) Ascaris lumbricoides
For each statement below, select the MOST APPROPRIATE parasite (A-E)
Use each choice (A-E) only once.
50. ingesting the eggs of this parasite causes neurocysticercosis
51. "giant roundworm" which can cause intestinal obstruction
52. autoinfection in immunocompromised individuals can lead to fatal hyperinfection
53. infections with this parasite can lead to seizures due to egg deposition in CNS
54. common cause of blindness
80. Which of the following BEST characterizes Leishmaniasis:
A) associated with cutaneous, mucocutaneous and visceral forms of disease.
B) transmitted by sandfly vectors.
C) associated with a parasite able to infect macrophages.
D) All of the above.
82. Schistosoma mansoni primarily causes inflammation located in the
A) bone marrow
B) lung alveoli
C) intestinal venules
D) renal tubules
E) meninges
Answers
Section 1
15-B, 16-E, 17-B, 23-D, 24-A, 49-D, 50-E, 51-A, 52-C, 53-B, 57-B, 65-C
Section 2
6-E, 28-B, 33-C, 37-C, 50-B, 51-C, 52-E, 53-D
Section 3
1-C, 32-E, 33-B, 45-A, 46-D, 47-E, 48-C, 49-B,
18-C, 19-C, 21-B, 23-E, 31-D, 59-C, 60-E, 64-D, 79-D
Section 4
9-B, 10-E, 12-D, 37-D, 74-A, 61-D, 97-C, 98-C
Section 5
1-E, 2-C, 3-D, 4-B, 5-E, 7-B, 8-A, 9-D, 10-B, 49-E, 50-D, 56-56-C
Section 6
3-C, 4-D, 5-C, 6-E, 34-E, 35-D, 50-D, 51-E, 52-A, 53-C, 54-B, 80-D, 82-C
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