M08 - Parasitology

  1. Match the blood parasite below with its vector.

    +reduviid bug
    +tsetse fly
    +Anopheles mosquito

    -Trypanosoma brucei
    -Leishmania sp
    -Trypanosoma cruzi
    -Plasmodium sp.
    • reduviid bug: Trypanosoma cruzi
    • tsetse fly: Trypanosoma brucei
    • sandfly: Leishmania sp
    • Anopheles mosquito: Plasmodium sp.
  2. Which of the following should NOT be used for concentration of parasitic cysts, eggs, or larva from stool specimens?

    B)  Modified PVA
  3. When preparing to preserve stool specimens for further examination, you want what ratio of preservative to stool?

    C) 3 to 1
  4. This photo shows a modified acid-fast stain performed on lung tissue.  What is the name of the infectious agent?
    Image Upload 1

    A)  Cryptosporidium parvum
  5. Which of the following intestinal protozoa has no cyst stage, ranges from 9 to 12 microns in diameter, and has two nuclei?

    D)  Dientamoeba fragilis
  6. The appropriate specimen for detection of Plasmodium spp or trypanosomes is

    D)  thick and thin blood films
  7. Match the following fluke organisms with their common names.

    +Fasciola spp.
    +Clonorchis sinensis
    +Opisthorchis viverrini
    +Paragonimus westermani

    -Chinese liver fluke
    -Sheep liver fluke
    -Lung fluke
    -Southeast Asian liver fluke
    • Fasciola spp.: Sheep liver fluke
    • Clonorchis sinensis: Chinese liver fluke
    • Opisthorchis viverrini: Southeast Asian liver fluke
    • Paragonimus westermani: Lung fluke
  8. In cases of malaria, the primary exoerythrocytic cycle occurs in the:

    C)  liver
  9. The following organism was found in the fecal sample of a patient with diarrhea and elevated liver enzymes. Some organisms had the presence of ingested red blood cells in their cytoplasm. This organism is most likely:
    Image Upload 2

    B)  Entamoeba histolytica
  10. The parasite Toxoplasma gondii is acquired via the ingestion of infected oocysts from cat feces. A diagnosis is primarily made through:

    E)  serologic tests
  11. The flotation method of concentration is used primarily to recover

    A)  cysts and eggs from stool
  12. Taenia solium, which can grow to be 1.5 to 8 meters long, contains 7 to 13 lateral uterine branches along the proglottid. The intermediate host is:

    A)  pigs
  13. (T/F) PVA fixative is appropriate for permanent staining including the Trichrome stain.
  14. How are specimens collected for the detection of the organism shown here?
    Image Upload 3

    D)  Scotch Tape Test
  15. A medical laboratory scientist (MLS) is examining a thin blood film from a patient suspected of having Plasmodium infection. After examining the slide for 5 minutes and viewing approximately 100 oil immersion fields, the MLS does not observe any structures associated with Plasmodium. Which one of the following statements explains this discrepancy?

    A)  The MLS may have missed the organism; more than 300 fields should be viewed.
  16. A young couple was recently vacationing in Massachusetts where they spent a lot of time hiking. Two weeks after returning from their trip, one of them comes down with fevers that spike every three hours. A thin smear of her blood yields the associated photo. What arthropod vector is responsible for spreading this disease and what parasite is the cause of her symptoms?
    Image Upload 4

    Ixodes ticks
    Anopheles mosquitoes
    Tanabid flies
    Human body louse
    Toxoplasma gondii
    Babesia microti
    Plasmodium falciparum
    Giardia lamblia
    • Ixodes ticks
    • Babesia microti
  17. Match the following organism with the best diagnostic specimen.

    +Babesia microti
    +Toxoplasma gondii
    +Trichinella spiralis
    +Diphyllobothrium latum

    -striated muscle biopsy
    -blood smear
    • Babesia microti: blood smear
    • Toxoplasma gondii: serum
    • Trichinella spiralis: striated muscle biopsy
    • Diphyllobothrium latum: stool/feces
  18. Massive hemolysis, blackwater fever, and central nervous system involvement are most common sequelae of infection by:

    B)  Plasmodium falciparum
  19. Humans acquire infections with Diphyllobothrium latum adult worms by:

    A)  Ingestion of raw or undercooked fresh water fish
  20. A young girl from Arkansas presents with a history of abdominal pain. Hematologic tests show that she is anemic. An Ova and Parasite exam is ordered. The organism below is observed in her stool.
    What organism is this?
    Image Upload 5

    C)  Necator americana
  21. The duodenal capsule technique involves the collection of duodenal contents to examine the presence of which of the following parasites?

    C)  Giardia lamblia
  22. The examination of sputum maybe necessary to diagnose infection with:

    D)  Paragonimus westermani
  23. Cutaneous larva migrans is associated with which of the following organisms?

    D)  Toxocara canis
  24. A definitive diagnosis can be made in a Trichinella infection on the basis of which of the following findings?

    D)  Identification of encysted larvae through muscle biopsy
  25. Which specimen would be the best to collect to discover this organism?
    Image Upload 6

    A)  Vaginal or urethral swab
  26. The permanent stained smear protocol of the O&P examination:

    D)  is designed to facilitate the identification of intestinal protozoa.
  27. Which of the following parasitic stages is NOT usually detected after using a concentration technique?

    B)  trophozoites
  28. A 28 yr old AIDS patient presented with watery, profuse, non-bloody diarrhea. When antibacterial medications did not alleviate his condition, a specimen was sent for further examination. Routine culture did not produce growth. A wet preparation from concentrated sediment showed the following organism.
    What is this organism and to what group of parasites does it belong?
    Image Upload 7

    C)  Isospora, Coccidia
  29. When amebiasis is strongly indicated but no parasitic forms are detected from any of three submitted fecal samples, the next step might be

    B)  to collect material obtained from sigmoidoscopy and examine for parasites.
  30. A 17-year-old male with a severe eye infection admits that he does not clean his contact lenses as often as he should. His eye infection is most likely the result of which parasite?

    B)  Acanthamoeba spp.
  31. The eggs of which intestinal parasite are not commonly found in feces and must be detected by other diagnostic techniques?

    D)  Enterobius vermicularis
  32. Primary amoebic-encephalitis may appear as bacterial meningitis and is caused by:

    B)  Naegleria sp.
  33. More cyst forms of a parasite would be seen with which stool consistencies? (Select 2 answers)

    • Formed
    • Soft
  34. Please explain why a symptomatic patient should submit at least 3 different stool specimens from 3 different days to the lab for parasite examination:
    Individual examination of each of the three stool samples collected over a 9 day period increases the chances of detecting a parasite or it eggs that are constantly being removed from the body daily by natural flushing of the GI tract.
  35. Molecular methods, including PCR, have been developed to detect specific parasites in a stool specimen. Choose 3 parasitic organisms that the CDC currently tests for using PCR.

    Diphyllobothrium latum
    Entamoeba histolytica
    Cryptosporodium sp
    Necatur americanus (Hookworm)
    Naegleria fowleri
    Giardia lamblia
    Taenia saginata
    • Entamoeba histolytica
    • Cryptosporodium sp
    • Giardia lamblia
Card Set
M08 - Parasitology
M08 - Parasitology