Other Protozoa 2

Question 1

What are the important genera among the hemoflagellates?

Answer 1

Trypanosomes and Leishmania.

Question 2

Describe the transmission of hemoflagellates.

Answer 2

Vector-borne.

Question 3

What is unique about the life cycle of Leishmania?

Answer 3

Intracellular for part of their life cycle within the macrophages of their host.

Question 4

What are the vectors of African Animal Trypanosomiasis?

Answer 4

Tsetse flies.

Question 5

What is the host range of African Animal Trypanosomiasis and where are they found?

Answer 5

Large host range, found in Sub-Saharan Africa.

Question 6

Describe the trypanosome life cycle.

Answer 6

Tsetse flies are infected by taking a blood meal of an infected host. Procyclic forms grow and reproduce within the fly and are injected into a new host.

Question 7

How do trypanosomes evade host immune responses?

Answer 7

The parasite is able to change its variance-specific glycoprotein in response to some of the population dying via antibody response.

Question 8

What is the host response to trypanosomes changing their variance specific glycoprotein?

Answer 8

The immune system has to start all over and build new antibodies to the change in the parasitic VSG.

Question 9

What are the important trypanosome species to know?

Answer 9

T. brucei, T. evansi, T. equiperdum, T. cruzi.

Question 10

Describe T. brucei.

Answer 10

Seen in cattle in Africa; causes ‘sleeping sickness’ in humans; zoonotic.

Question 11

Describe T. evansi.

Answer 11

Causes disease in horses, camelids, and cattle; causes Surra in horses; found in Sub-Saharan Africa, Asia, and South America.

Question 12

Describe T. equiperdum.

Answer 12

Infects horses; causes Dourine.

Question 13

Describe T. cruzi.

Answer 13

Causes Chagas disease; found in South America.

Question 14

What are the clinical signs of trypanosoma in cattle?

Answer 14

Anemia, lymphadenopathy, wasting, lethargy, reduced productivity.

Question 15

Why does trypanosoma in cattle cause profound anemia?

Answer 15

All efforts of the bone marrow go to producing B and T cells.

Question 16

What are the control methods of African Animal Trypanosomiasis?

Answer 16

Genetic resistance with local breeds (N’Dama), protect non-resistant breeds, control of vectors via dipping, biological control, and surveillance.

Question 17

What is the treatment for AAT?

Answer 17

Chemoprophylaxis (melarsomine).

Question 18

How is AAT diagnosed?

Answer 18

Diagnosis through examination of blood buffy coat.

Question 19

Trypanosomiasis in horses is transmitted how?

Answer 19

Venereally or mechanically.

Question 20

What are the venereally transmitted tryps in horses?

Answer 20

T. equiperdum: Dourine.

Question 21

What are the mechanically transmitted tryps in horses?

Answer 21

T. evansi: Surra.

Question 22

Where do we find trypanosomiasis geographically in horses?

Answer 22

Africa, Asia, and South America.

Question 23

Is trypanosomiasis in horses notifiable?

Answer 23

Yes.

Question 24

T. theileri infects what species?

Answer 24

Cattle.

Question 25

T. melophagium infects what species?

Answer 25

Sheep.

Question 26

How is T. melophagium transmitted?

Answer 26

By Melophagium ovinus (sheep keds).

Question 27

What are the characteristics of T. theileri and T. melophagium?

Answer 27

Non-pathogenic, mechanically transmitted, very widespread.

Question 28

What does trypanotolerance mean?

Answer 28

Condition of hosts in which tryps do not cause disease.

Question 29

How is Leishmania transmitted?

Answer 29

To dogs, cats, and people by sandflies (Phlebotomus spp).

Question 30

What are the two forms of Leishmania?

Answer 30

Promastigote: flagella; Amastigote: no flagella.

Question 31

Describe the life cycle of Leishmania.

Answer 31

Biological transmission by sandfly via feeding on hosts; within mammalian host, the parasite infects macrophages.

Question 32

A lot of the growth of Leishmania occurs where?

Answer 32

In host macrophages.

Question 33

What are the two types of canine leishmania?

Answer 33

Cutaneous and visceral.

Question 34

Describe cutaneous canine leishmania.

Answer 34

Lesions local to sandfly bite; granulomas form as a result of host immune response; lymphadenopathy.

Question 35

Describe visceral canine leishmania.

Answer 35

Dissemination from skin via blood and lymph to spleen, liver, bone marrow, etc.; prognosis much worse than the cutaneous variety.

Question 36

Describe the clinical signs of canine leishmania.

Answer 36

Variable; chronic diarrhea sometimes is the first sign.

Question 37

What are the methods of diagnosis of canine leishmania?

Answer 37

Parasite stages found in biopsies; serology and molecular ID.

Question 38

What are the treatment options for canine leishmania?

Answer 38

Limited range of drugs such as allopurinol or miltefosine; vx which is recombinant against 5 proteins and induces Th1 response.

Question 39

What are the methods of control of leishmania in canines?

Answer 39

Protection against sandflies; eradication campaigns in some areas.

Question 40

What are the areas in which zoonotic Leishmaniasis is a concern?

Answer 40

Rare in USA except TX; less rare in South America, Africa, and Asia; increasingly diagnosed in southern Europe.

Question 41

In what species is Cytauxzoon felis found?

Answer 41

Wild felid (reservoirs).

Question 42

What are the vectors of Cytauxzoon felis?

Answer 42

Amblyomma americanum and Dermacentor variables ticks.

Question 43

What are the clinical signs of Cytauxzoon felis?

Answer 43

Leukopenia and inflammatory blood picture.

Question 44

What organisms cause avian malaria?

Answer 44

Plasmodium and Haemoproteus spp.

Question 45

Avian malaria is a major disease of what species?

Answer 45

Penguins; clinically silent in other avian species.

Question 46

How is avian malaria transmitted?

Answer 46

By mosquitoes.