BOC Study Guide (CHAPTER REVIEW)

Question 1

1. Artifacts found in a stool specimen that can be confused with ova or cyst are:

A. partially digested meat fibers
B. degenerated cells from the gastrointestinal mucosa
C. dried chemical crystals
D. pollen grains

Answer 1

D. pollen grains

Question 2

2. Polyvinyl alcohol used in the preparation of permanently stained smears of fecal material:

A. concentrated eggs
B. dissolves artifacts
C. serves as an adhesive
D. enhances stain penetration

Answer 2

C. serves as an adhesive

Question 3

3. A method to culture Acanthamoeba species from corneal ulcer scrapings is to inoculate

A. McCoy cells
B. Novy, MacNeal and Nicolle (NNN) medium
C. an agar plate overlaid with Escherichia coli
D. Regan-Lowe medium

Answer 3

C. an agar plate overlaid with Escherichia coli

Question 4

4. Primary amoebic encephalitis is caused by:

A. Entamoeba coli
B. Dientamoeba fragilis
C. Endolimax nana
D. Naegleria fowleri

Answer 4

D. Naegleria fowleri

Question 5

5. A formed stool is received in the laboratory at 10:30PM for ova and parasite exam. The night shift technologist is certain that the
   workload will prevent the examination of specimen until 7AM when the next shift arrives. The technologist should:

A. request that a new specimen be collected after 7AM
B. hold the specimen at room temperature
C. examine a direct prep for trophozoites and freeze the
remaining specimen
D. preserve the specimen in formalin until it can be examined

Answer 5

D. preserve the specimen in formalin until it can be examined

Question 6

6. The advantage of thick blood smears for malarial parasites is to:

A. improve staining of the organisms
B. improve detection of the organisms
C. remove RBC artifacts
D. remove platelets

Answer 6

B. improve detection of the organisms

Question 7

7. This parasite is transmitted by accidental ingestion of cat feces that contain oocysts and by ingestion of undercooked meat that has tissue cysts. The parasite is:

A. Cryptosporidium parvum
B. Cyclospora cayetanensis
C. Toxoplasma gondii
D. Trypanosoma cruzi

Answer 7

C. Toxoplasma gondii

Question 8

8. A 44-year-old man is admitted to the hospital following a 2-week history of low-grade fever, malaise, and anorexia. Examination of a Giemsa stain reveals many intraerythrocytic parasites. Further history reveals frequent camping trips near Martha’s Vineyard and Nantucket Island, but no travel outside the continental United States. This parasite can be easily confused
   with:

A. Trypansoma cruzi
B. Trypanosoma rhodesiense/gambiense
C. Plasmodium falciparum
D. Leishamania donovani

Answer 8

C. Plasmodium falciparum

Question 9

9. A Wright-stained peripheral smear reveals the following:
   ● Erythrocytes enlarged ½ to 2x normal size
   ● Schüffner dots
   ● Parasites with irregular “spread out” trophozoites,
   golden-brown pigment
   ● 12-24 merozoites
   ● Wide range Stages

This is consistent with Plasmodium:

A. falciparum
B. malariae
C. ovale
D. vivax

Answer 9

D. vivax

Question 10

10. A patient is suspected of having amoebic dysentery. Upon microscopic examination of a fresh fecal specimen for ova and
    parasites, the data shown are obtained:
    ● a trophozoite of 25 μm
    ● progressive, unidirectional crawl
    ● evenly distributed peripheral chromatin
    ● finely granular cytoplasm

This information indicates:

A. Entamoeba coli
B. Entamoeba histolytica
C. Endolimax nana
D. Iodamoeba bütschlii

Answer 10

B. Entamoeba histolytica

Question 11

Trophozoites of the cyst shown in the image are likely to:

A. contain red blood cells
B. have clear, pointed pseudopodia
C. contain few, if any, vacuoles
D. have slow, undefined motility

Answer 11

D. have slowed, undefined motility

Question 12

13. Which organisms are shown together in the image?

A. Entamoeba histolytica and Entamoeba hartmanni
B. Dientamoeba fragilis and Entamoeba histolytica
C. Giardia lamblia and Entamoeba coli
D. Entamoeba coli and Entamoeba histolytica

Answer 12

A. Entamoeba histolytica and Entamoeba hartmanni

Question 13

12. Upon finding the organism show in a fecal concentrate, the technologist should:

A. immediately telephone the report of this pathogen to the physician
B. review the fecal concentration carefully for the presence of other microorganisms that may be pathogenic
C. look for motile trophozoites
D. request a new specimen because the presence of excessive pollen grains

Answer 13

B. review the fecal concentration carefully for the presence of other microorganisms that may be pathogenic

Question 14

14. This structure on the right in the image depicts a:

A. cyst of a nonpathogenic amoeba
B. trophozoite of a nonpathogenic amoeba
C. cyst of a pathogenic amoeba
D. trophozoite of a pathogenic amoeba

Answer 14

A. cyst of a nonpathogenic amoeba

Question 15

15. The organism shown in the image is a(n):

A. cyst of a nonpathogenic amoeba
B. trophozoite of a nonpathogenic amoeba
C. cyst of a pathogenic amoeba
D. trophozoite of a pathogenic amoeba

Answer 15

B. trophozoite of a nonpathogenic amoeba

Question 15

16. A 24-year-old woman, who just returned from vacationing in Lebanon, becomes ill with diarrhea. The organism shown in the image are found in her stool. The patient most likely is suffering from:

A. giardiasis
B. amebiasis
C. ascariasis
D. balantidiasis

Answer 15

A. giardiasis

Question 16

17. A liquid stool specimen is collected at 10:00PM and brought to the laboratory for culture and ova and parasite examination. It is
    refrigerated until 10:10AM the next day, when the physician requests that the technologist look for amoebic trophozoites. The best course of action would be to:

A. request a fresh specimen
B. perform a concentration of the original specimen
C. perform a trichrome stain on the original specimen
D. perform a saline wet mount on the original specimen

Answer 16

A. request a fresh specimen

Question 17

18. Small protozoan cyst are found in a wet mount of sediment from ethyl-acetate concentrated material. Each cyst has 4 nuclei
    that do not have peripheral chromatin, and each nucleus has a large karyosome, which appears as a refractive dot. These oval
    cysts are most likely:

A. Endolimax nana
B. Chilomastix mesnili
C. Entamoeba histolytica
D. Entamoeba hartmanni

Answer 17

A. Endolimax nana

Question 18

19. The term “internal autoinfection” is generally used in referring to infections with:

A. Ascaris lumbricoides
B. Necator americanus
C. Trichuris trichiura
D. Strongyloides stercoralis

Answer 18

D. Strongyloides stercoralis

Question 19

20. A fibrous skin nodule is removed from the back of a patient for Central America. A microfilaria is seen upon microscopic exam of the nodule is most likely:

A. Wuchereria bancrofti
B. Brugia malayi
C. Onchocerca volvulus
D. Loa loa

Answer 19

C. Onchocerca volvulus

Question 20

21. The egg shown in the image is most likely to be found in children suffering from: (ENTEROBIOUS VERMICULARIS)

A. diarrhea
B. constipation
C. perianal itching
D. stomach pain

Answer 20

C. perianal itching

Question 21

22. The specimen of choice for finding the parasite shown in the image is: (ENTEROBIOUS VERMICULARIS)

A. stool
B. duodenal washing
C. rectal swab
D. scotch tape preparation

Answer 21

D. scotch tape preparation

Question 22

24. The causative agent of cysticercosis is:

A. Taenia solium
B. Taenia saginata
C. Ascharis lumbricoides
D. Trichuris trichiura

Answer 22

A. Taenia solium

Question 23

23. Human feces is not a recommended specimen in the detection of:

A. Strongyloides stercoralis
B. Entamoeba histolytica
C. Echinococcus granulosus
D. Ancylostoma duodenale

Answer 23

C. Echinococcus granulosus

Question 24

25. Organisms that can be easily identified to the species level from the ova in fecal specimens include: A. Metagonimus yokogawai, Heterophyes heterophyes B. Taenia solium, Taenia saginata C. Necator americanus, Ancylostoma duodenale D. Paragonimus westermani, Hymenolepis nana

Answer 24

D. Paragonimus westermani, Hymenolepis nana

Question 25

26. The preferred specimen for the diagnosis of paragonimiasis is: A. bile drainage B. blood smear C. skin snips D. sputum

Answer 25

D. sputum

Question 26

27. A stool specimen for ova and parasite examination contained numerous rhabditiform larvae. Which factor(s) aid in the identification of larvae? A. larva tail nuclei and presence of sheath B. length of buccal cavity and appearance of genital primordium C presence of hydatid cysts D. prominent kinetoplasts in trypomastigote

Answer 26

B. length of buccal cavity and appearance of genital primordium

Question 27

28. Which one of the following routine tests for Entamoeba histolytica has the highest sensitivity and specificity? A. colonic ulcer biopsy B. stool microscopy C. stool EIA D. urine PCR

Answer 27

C. stool EIA

Question 28

30. Which characteristic will identify Iodamoeba bütschlii? A. nuclei in mature cyst B. small (5-10 μm) size C. prominent vacuole in cyst form D. presence of up to 8 nuclei in the cyst form

Answer 28

C. prominent vacuole in cyst form

Question 29

29. What is the principal means of distinguishing Entamoeba histolytica from Entamoeba hartmanni by light microscope? A. size of trophozoite B. appearance of karyosome C appearance of nuclear chromatin D. number of nuclei in cyst form

Answer 29

A. size of trophozoite

Question 30

31. The only medically significant ciliate organism is: A. Acanthamoeba B. Balantidium coli C Cryptosporidium parvum D. Chilomastix mesnili

Answer 30

B. Balantidium coli

Question 31

32. Where do Plasmodium sporozoites proliferate? A. bone marrow B. liver C red blood cells D. nucleated erythrocyte precursors

Answer 31

B. liver

Question 32

33. Individuals who lack the Duffy antigen on the surface of the red blood cells are protected against which species of Plasmodium? A. P. vivax B. P. falciparum C P. malariae D. P. ovale

Answer 32

A. P. vivax

Question 33

34. Which nematodes produce eggs with characteristic hyaline polar plugs at each end, as in the image? A. Ascaris lumbricoides B. Necator americanus C Strongyloides stercoralis D. Trichuris trichiura

Answer 33

D. Trichuris trichiura

Question 34

35. Which nematodes has a characteristic mamillated bile-stained egg, as in the image? A. Ascaris B. Necator C Strongyloides D. Trichuris

Answer 34

A. Ascaris

Question 35

36. Which organism is predominantly responsible for visceral larva migrans? A. Ancylostoma braziliensis B. Onchocerca volvulus C Toxocara canis D. Trypanosoma brucei

Answer 35

C Toxocara canis

Question 36

37. Which organism has the largest egg? A. Clonorchis B. Diphyllobothrium C Fasciola D. Paragonimus

Answer 36

C Fasciola

Question 37

38. The eggs of which species of Schistosoma can be isolated from urine? A. S. haematobium B. S. japonicum C S. mansoni D. S. sterooralis

Answer 37

A. S. haematobium

Question 38

39. Which one of the following features of Taenia saginata helps distinguish it from T. solium? A. egg with a radially striated wall B. pork tapeworm C proglottid with <13 uterine branches D. unarmed rostellum

Answer 38

D. unarmed rostellum

Question 39

40. Infection by this organism can cause of B12 deficiency: A. Diphyllobothrium latum B. Echinococcus granulosus C Taenia solium D. Schistosoma manson

Answer 39

A. Diphyllobothrium latum

Question 40

41. This organism is responsible for hydatid cysts of the liver: A. Diphyllobothrium B. Echinococcus C Hymenolepis D. Trichomonas

Answer 40

B. Echinococcus

Question 41

42. How is Trichomonas vaginalis transmitted? A. ingestion of cyst stage B. ingestion of trophozoite stages C larval stage burrows through the skin D. Sexual contact

Answer 41

D. Sexual contact

Question 42

43. This parasite has the following characteristics: ● Banana shaped gametocytes in RBCs ● Multiple ring forms in RBCs ● All Rbcs are infected The identification of the parasite is: A. Plasmodium falciparum B. Plasmodium malariae C Plasmodium ovale D. Plasmodium vivax

Answer 42

A. Plasmodium falciparum

Question 43

44. This parasite has the following characteristics: ● Stains red with acid-fast stain ● Zoonotic transfer to humans ● Spread by fecal-oral route The most likely organism is: A. Cryptosporidium B. Giardia C Naegleria fowleri D. Necator

Answer 43

A. Cryptosporidium