PARASITOLOGY - Blood Borne parasites

Question 1

List four methods of parasite control

Answer 1

Vector control
Rotational grazing
Drugs
Vaccinations

Question 2

What is the main risk of overusing drugs for parasite control?

Answer 2

Drugs put selective pressures on the parasites, causing them to evolve and become resistant

Question 3

List three methods of parasite prevention

Answer 3

Hygiene
Biosecurity
Vector eradication

Question 4

What are three examples of blood borne parasites?

Answer 4

Babesia
Leishmania
Dirofilaria

Question 5

What type of parasite is Babesia?

Answer 5

Babesia is a protozoan parasite

Question 6

What type of lifecycle do Babesia have?

Answer 6

Babesia have an indirect lifecycle

Question 7

What are the final and intermediate hosts for Babesia?

Answer 7

Final hosts: Dogs, cattle, sheep, horses, humans
Intermediate host: Ixodes (tick)

Question 8

Where do Babesia replicate within their final host?

Answer 8

Babesia replicate within the erythrocytes of their final host

Question 9

Describe the lifecycle of the Babesia parasite

Answer 9

1. Babesia gametes formed within the erythrocytes –>
2. Gametes are ingested by tick during a blood meal –>
3. Sexual reproduction occurs forming sporozoites which migrate to the salivary glands of the tick –>
4. Sporozoites enter the erythrocytes of the host through the tick saliva injected at the feeding site –>
5. Asexual reproduction occurs within the erythrocytes forming merozoites –>

Question 10

What can be done to diagnose babesiosis?

Answer 10

PCR test
Identifying babesia on a blood smear

Question 11

Which drug can be used to treat babesiosis?

Answer 11

Imidocarb can be used to treat babesiosis

Question 12

What are the clinical signs of babesiosis in cattle?

Answer 12

Pyrexia
Haemolytic anaemia
Haemoglobinuria
Jaundice
Tachycardia

Question 13

What type of parasite is Leishmania?

Answer 13

Leishmania is a protozoan parasite

Question 14

What type of lifecycle does Leishmania have?

Answer 14

Leishmania has an indirect lifecycle

Question 15

What are the final and intermediate hosts for Leishmania?

Answer 15

Final hosts: Dogs, humans, wild animals
Intermediate host: Sandfly

Question 16

Where do Leishmania replicate within their final host?

Answer 16

Leishmania replicate within the macrophages of they final host

Question 17

Describe the lifecycle of Leishmania

Answer 17

1. Amastigotes are ingested by the sandfly in a blood meal ->
2. Amastigotes undergo asexual reproduction within the sandfly –>
3. Amastigotes develop into promastigotes which migrate to the sandfly salivary glands –>
4. Promastigotes enter the macrophages of the host through the sandfly saliva injected at the feeding site –>
5. Promastigotes develop into amastigotes which undergo asexual reproduction within the macrophages –>

Question 18

How does the Leishmania parasite achieve immune evasion?

Answer 18

Amastigotes hide within the host macrophages where they can disrupt macrophage function, decreasing the reactive oxygen intermediates and lysosomal activity

Question 19

What can be done to diagnose Leishmania?

Answer 19

PCR test
Skin biopsy
Identifying Leishmania on a blood smear

Question 20

Which drug can be used to treat Leishmania?

Answer 20

Allopurinol can be used to treat Leishmania

Question 21

What are the clinical signs of Leishmania?

Answer 21

Hair loss
Skin ulcers
Eczema
Lymph node enlargement

Question 22

What type of parasite if Dirofilaria?

Answer 22

Dirofilaria is a nematode

Question 23

What type of lifecycle does Dirofilaria have?

Answer 23

Dirofilaria has an indirect lifecycle

Question 24

What are the final and intermediate hosts for Dirofilaria?

Answer 24

Final host: Dogs
Intermediate host: Mosquito

Question 25

Where do adult dirofilariae reside within their final host?

Answer 25

Adult dirofilariae reside within the right side of the heart in their final host

Question 26

Where do dirofilaria micorfilarae (L1) reside within their final host?

Answer 26

Microfilarae (L1) circulate the host bloodstream

Question 27

Describe the lifecycle of Dirofilaria

Answer 27

1. Mosquito ingests the microfilariae in a blood meal --> 2. Microfilariae mature into infective juveniles --> 3. The invective juveniles enter the host bloodstream when the mosquito feeds --> 4. Juveniles migrate to the right side of the heart and mature into adult nematodes --> 5. Female nematodes produce microfilariae -->

Question 28

Which drug can be used to prevent the development of microfilariae?

Answer 28

Ivermectin

Question 29

What are the clinical signs of heartworm?

Answer 29

Chronic cough Exercise intolerance Cardiovascular dysfunction