Blood and Tissue Parasites 2

Question 1

What are the prevalence/distribution and transmission vector for Babesiosis vs. Lyme Disease vs. Anaplasmosis?

Answer 1

They are exactly the same: all are transmitted by Ixodes ticks throughout the U.S. (esp. West coast, NE, and Midwest)

Question 2

How does the clinical picture of Babesiosis differ between the NE and Midwest+West Coast?

Answer 2

The NE version presents like P. vivax, with an incubation period of about 2 weeks; the other version is fulminant: occurs quickly, suddenly, and often lethally with fever and hemolysis

Question 3

Histologically, Babesia microti and Plasmodium falciparum rings in infected RBCs can look very similar. What stain should be used to ensure a correct diagnosis?

Answer 3

Giemsa stain

Question 4

Which do Babseia or P. falciparum tend to have: granular remains of hemoglobin degradation in the RBC, “messy” and elongated ring forms, “Maltese cross” formation.

Answer 4

Plasmodium has the granular remains, which are known as “malaria pigment”; Babesia has elongated ring forms and (rarely!) Maltese cross formations

Question 5

Name 2 tick-borne “emerging diseases” that infect WBCs and form morulae.

Answer 5

Anaplasma and Ehrlichia (morulae describe a microcolony / mass of infected cells that can be observed in blood film)

Question 6

Give the disease names and vectors for Trypanosoma cruzi and Trypanosoma brucei.

Answer 6

Cruzi - Chaga’s disease, transmitted by reduvid kissing bugs

Brucei - African sleeping sickness, transmitted by tsetse flies

Question 7

Trypanosoma cruzi can take 2 forms in a human host. Name the 2 forms and say where each form is observed.

Answer 7

Amastigote - in tissue, can infect heart and colon

Trypomastigote - in bloodstream

Question 8

What is the vector for Leishmaniasis, and where in the human body do they multiply?

Answer 8

Sand fly; multiplication occurs in histiocytes (stationary WBCs of skin, liver, etc.)

Question 9

List the 3 classifications of Leishmaniasis lesions

Answer 9

Cutaneous, mucocutaneous, and visceral

Question 10

Which form of Leishmaniasis is characterized by chronic skin ulcers, which sometimes occur distant from the initial sandfly bite?

Answer 10

Cutaneous Leishmaniasis

Question 11

Which form of Leishmaniasis is characterized by skin ulcers that spread to the mouth and nasopharynx, and can be accompanied by secondary bacterial infection?

Answer 11

Mucocutaneous Leishmaniasis

Question 12

Which form of Leishmaniasis is characterized by fever, weight loss, anorexia, and hepatosplenomegaly?

Answer 12

Visceral Leishmaniasis

Question 13

What definitive host of Toxoplasma gondii can transmit the parasite via its feces?

Answer 13

Cats

Question 14

What kind of symptoms does Toxoplasmosis cause in immunocompetent people, and how long do they last?

Answer 14

Mild “flu-like” symptoms of several weeks duration

Question 15

If a pregnant woman acquires Toxoplasmosis, she may miscarry, her child may be stillborn, or it may be born with problems in what 2 parts of the body?

Answer 15

the head (abnormally large or small) and the eyes (ex. retinochoroiditis, inflammation, loss of vision)

Question 16

Toxoplasmosis in what type of patient can cause fever, confusion, headache, seizures, nausea, and poor coordination?

Answer 16

HIV patients

Question 17

If a person with AIDS acquires or reactivates Toxoplasmosis, what is the major problem that may occur?

Answer 17

CNS disease

Question 18

What 2 filarial organisms most commonly cause lymphatic filariasis / elephantiasis?

Answer 18

Wuchereria bancrofti and Brugia malayi

Question 19

What filarial organism can cause river blindness, and what is its vector?

Answer 19

Onchocerca volvulus / Onchocerciasis, from the blackfly

Question 20

The cutaneous manifestations of what filarial organism involves skin rash, depigmentation, unrelenting itch, inflammation, swelling, and severe dermatitis? It is sometimes called “lizard skin” or “leopard skin.”

Answer 20

Onchocerca volvulus / Onchocerciasis