Protozoa & Helminths

Question 1

Nematodes vs. Trematodes vs. Cestodes shape

Answer 1

Nematodes are long and circular
Trematodes are flat like pancakes
Cestodes are segmented, but also long.

Question 2

Travel in the Middle East, bitten and got sick with fever weight loss, splenomegaly

Answer 2

Sand fly bites - Leishmania donovani

Question 3

Little dots in pairs inside of a macrophage

Answer 3

Amastigotes

Question 4

Promastigotes are found in the __ of the vector

Answer 4

Saliva

Question 5

Difference between promastigote vs. amastigote vs. trypomastigotes

Answer 5

Promastigote has flagellum posterior to the kinetoplast and no attachment to body of the parasite

Amastigotes have kinetoplasts and nucleus, but no flagellum

Trypomastigotes have flagella that come out the same end as promastigotes, but wrap around the posterior body.

Question 6

45 y/o businessman in Rio with sickness months later. He had splenomegaly and facial edema

Answer 6

Chagas disease - Trypanosoma cruzi from the Reduviid bug

Question 7

What bug causes visceral leishmaniasis?

Answer 7

Leishmania donovani

Question 8

Can you distinguish between Chagas and visceral leishmaniasis on a generalized histo slide?

Answer 8

No

Question 9

What kind of -mastigote does Chagas display?

Answer 9

Trypomastigotes

Question 10

Are trypanosomes associated with a host cell?

Answer 10

No, they are only found in blood.

Question 11

30 y/o female with bloody diarrhea with mucus and blood flecks. Mexico 3 weeks ago.

Answer 11

Entamoeba histolytica

Question 12

Amebiasis is caused by which organism?

Answer 12

Entamoeba histolytica

Question 13

How do you diagnose Amebiasis

Answer 13

Serology and/or trophozoites (with RBCs in the cytoplasm) or cysts (with up to 4 nuclei) in stool

Question 14

How is amebiasis transmitted?

Answer 14

Cysts in water

Question 15

What protozoa causes giardiasis?

Answer 15

Giardia lambia

Question 16

How is giardiasis diagnosed?

Answer 16

Trophozoites or cysts in stool

Question 17

How does giardiasis present?

Answer 17

Bloating, flatulence, foul-smelling, fatty diarrhea . Often seen in campers/hikers.

Question 18

A person with a CD4+ count of

Answer 18

Cryptosporidium

Question 19

How is cryptosporidium transmitted?

Answer 19

Oocysts in water. They stain acid-fast.

Question 20

Female with + tests for gonorrhea and chlamydia. Wet prep of discharge shows another organism

Answer 20

Trichomoniasis - Trichomonas vaginalis - trophozoite protozoa

Question 21

Peace corp volunteer - chronic diarrhea for 4 wks, weight loss, abdominal pain, nausea prior to eating

Answer 21

Giardia lambia

Question 22

Chorioretinitis + hydrocephalus + intracranial calcifications = what?

Answer 22

Congenital toxoplasmosis

Question 23

HIV + 60 CD4 + intermittent diarrhea + inappropriate speech

Answer 23

Cryptosporidium and toxoplasma

Question 24

How is toxoplasma gondii transmitted?

Answer 24

Cysts in meat; oocysts in cat feces; crosses the placenta

Question 25

How is toxo diagnosed?

Answer 25

Serology, biopsy (tachyzoite)

Question 26

How is toxo treated?

Answer 26

Sulfadiazine + pyrimethamine

Question 27

What is an oocyst?

Answer 27

Product of sexual reproduction of these protozoa

Question 28

A person comes to the ER with signs of meningoencephalitis. Their history is positive for having been swimming in freshwater lakes. What do they have?

Answer 28

Naegleria fowleri

Question 29

How do the naegleria fowleri end up in CSF?

Answer 29

Take a watery passage through your nose via the cribriform plate.

Question 30

What organism causes african sleeping sickness?

Answer 30

Trypanosoma brucei

Question 31

How is Trypanosoma brucei transmitted?

Answer 31

Tsetse fly - painful bite

Question 32

How does African sleeping sickness present?

Answer 32

Enlarged lymph nodes, recurring fever, somnolence, coma

Question 33

Why do people with african sleeping sickness keep getting recurring fever?

Answer 33

Due to antigenic variation of the organism.

Question 34

What is characteristic of tertian malaria?

Answer 34

Fever 2x in the last 4 days (48 hr cycle time)

Question 35

2 parasties within one RBC is typical of which form of malaria?

Answer 35

Falciparum

Question 36

Where are schizont's normally trapped?

Answer 36

Capillaries

Question 37

What vector exists for plasmodium species?

Answer 37

The anopheles mosquito

Question 38

What is the cycle time for P. malariae?

Answer 38

72 hr cycle

Question 39

Ascites, splenomegaly, umbilical hernia, superficial abdominal veins

Answer 39

Schistosoma japonicum

Question 40

The lateral spike in the embrionated egg of a schistosome tells you it is which type?

Answer 40

Mansoni

Question 41

Schistosome with a terminal spine indicates which type?

Answer 41

S. haematobium

Question 42

Fever + hemolytic anemia after a long hike

Answer 42

Babesiosis

Question 43

Babesiosis caused by what?

Answer 43

Babesia transferred by Ixodes tick

Question 44

Maltese cross on blood smear

Answer 44

Babesiosis

Question 45

Are plasmodium embrionated eggs unicellular?

Answer 45

No, they are multicellular

Question 46

Elephantiasis

Answer 46

Filiaria species - Wuchereria bancrofti

Question 47

All of the dots in the worm of elephantiasis

Answer 47

Nuclei of the multicellular organism - the different tissues of the parasites

Question 48

Unilateral lymphedema

Answer 48

Pathognomonic for filiariasis

Question 49

Likes raw sausages + periorbital edema and conjunctivitis

Answer 49

Trichinella spiralis

Question 50

What kind of disease is trichinella producing?

Answer 50

Intestinal infection; larvae enter bloodstream and encyst in striated muscle cells --> inflammation of the muscle Trichinosis - fever, vomiting, nausea, periorbital edema, myalgia

Question 51

What causes the conjunctivitis of trichinella?

Answer 51

The larvae creepy crawling across your eye.

Question 52

Perianal pruritus

Answer 52

Enterobius vermicularis (pinworm)

Question 53

How do you diagnose pinworm infection?

Answer 53

See egg on a scotch tape test

Question 54

How common is a pinworm infection?

Answer 54

The most common helminth infection in kids

Question 55

Cramps + diarrhea + worm in stool

Answer 55

Ascaris lumbricoides (giant roundworm)

Question 56

How do you get roundworm?

Answer 56

Fecal-oral route - infection with possible obstruction at ileocecal valve

Question 57

What is characteristic of the shape ascaris egg?

Answer 57

Rugged surface in fresh stool

Question 58

What is specific about maturation of the ascaris egg?

Answer 58

It must mature outside of the body. Requires lower temperature. No auto-infection

Question 59

Adenocarcinoma, WWII, Corticosteroids, Nausea, Vomiting purulent sputum

Answer 59

Strongyloides stercoralis

Question 60

What other organisms have a lung cycle?

Answer 60

Ascaris lumbricoides | Strongyloides stercoralis

Question 61

Seizure, central america, cyst lesions in brain, ova in stool

Answer 61

Taenia solium - tapeworm causing neurocysticercosis

Question 62

What do you treat neurocysticercosis with?

Answer 62

Albendazole

Question 63

Radiating appearance of eggs in stool

Answer 63

Pathognomonic for cestodes especially taenia solium

Question 64

Scolex Hooks

Answer 64

Taenia solium

Question 65

Can taenia solium autoinfect?

Answer 65

Yes.