Protozoa and Worms

Question 1

What are the three groups of protozoans?

Answer 1

• Amebae: single-celled organisms
• Flagellates: distinguished by flagellum
• Coccidians: have structures that resemble cocci

Question 2

What are the three groups of helminths?

Answer 2

• Trematodes: Schistosoma
• Nematodes: Ascaris, Strongyloides, Ancylostoma, Necator, Enterobius, Trichinella, Wuchereria
• Cestodes: Taenia, Diphyllobothirum, and Echinococcus

Question 3

Visceral Leishmaniasis will present with ________________ in the cytoplasm of macrophages.

Answer 3

amastigotes

Question 4

The ____________ form of Leishmania is transmittable.

Answer 4

promastigote

Question 5

Describe the forms of amastigote, promastigote, epimastigote, and trypomastigote.

Answer 5

• Amastigote: small, circular, tiny flagellum
• Promastigote: elongated, flagellum present on the tip of organism
• Epimastigote: elongated, flagellum coming from middle of organism
• Trypomastigote: elongated, flagellum comes from opposite end of organism as the tapered tip

Question 6

Sketchy notably omitted one sign from Chagas disease: ___________.

Answer 6

Romaña’s sign –periorbital edema

Question 7

What histologic sample is characteristic of E. histolycia?

Answer 7

RBCs within trophozoites (like the red cups in the trophozoite puddle)

Question 8

Trichomonas has multiple ___________ and does not make _____________.

Answer 8

flagella; cysts

Question 9

_____________ staining can reveal Giardia lamblia.

Answer 9

Trichrome

Question 10

______________ are characteristic of amastigotes.

Answer 10

The “pair of dots” sign

Question 11

Cyclospora is often confused with Cryptosporidium because both stain acid-fast. How are they different?

Answer 11

Cyclospora is larger

Question 12

How can you differentiate schizonts from gametocytes?

Answer 12

Schizonts are round cells with many round dots inside. Gametocytes are longer and slender.

Question 13

A patient presents with myalgia after making sausage. What other symptoms might he have?

Answer 13

Conjunctivitis and vomiting (like Mr. Porky with the red glasses and green drool)

Question 14

What shape is typical of the Enterobius vermicularis egg?

Answer 14

Flat on one side and curved on the other

Question 15

What nematodes have a pulmonary phase?

Answer 15

• Strongyloides stercoralis

* Ascaris lumbricoides

Question 16

Where can the cysts of Taenia travel in cysticercosis?

Answer 16

Anywhere in the body – skin, eye, brain

Question 17

______________ can look a lot like Leishmaniasis.

Answer 17

The leishmanial form of Trypanosoma cruzi (which produces facial edema, lymphadenopathy, hepatosplenomegaly, and fever)

Question 18

What would you see in a non-fresh sample of E. histolytica stool?

Answer 18

Only cysts –the trophozoite form will break

Question 19

What two histologic presentations may be seen in Toxoplasma samples?

Answer 19

• Pseudocysts inside macrophages

* Trohpozoites (banana-shaped)

Question 20

What sizes are Cryptospora and Cyclospora?

Answer 20

• Crypto: 4 - 6 um

* Cyclo: 8 - 10 um

Question 21

Which intestinal nematode is big enough to be confused with earthworms?

Answer 21

Ascaris lumbricoides

Question 22

What anatomic sign distinguishes A. lumbricoides from earthworms?

Answer 22

Ascaris has longitudinal muscles