Blood borne parasites

Question 1

Name 2 examples of blood borne protozoan parasites

Answer 1

Babesia and leishmania.

Question 2

What hosts can babesia infect?

Answer 2

Cattle, dogs, horses, sheep, pigs and humans.

Question 3

How is babesia trasmitted?

Answer 3

Indirectly via tick vector.

Question 4

Where in the host does babesia parasite locate?

Answer 4

Erythrocytes, where it replicates.

Question 5

What are the consequences of babesia infection?

Answer 5

Severe haemolytic anaemia; up to 75% of RBC are destroyed.

Question 6

How can babesiosis be treated?

Answer 6

With Imidocarb or aracacides to kill the tick infestation.

Question 7

Describe the lifecyle of babesia

Answer 7

1. Tick ingests infected hosts blood. RBC’s contain gametes that replicate by sexual reproduction.
2. Sporozoites form and migrate to the salivary glands of the tick.
3. Tick bites host and injects saliva causing the sporozoites to enter vertebrate host blood stream.
4. Sporozoites enter RBC and multiply by asexual reproduction to form merozoites.
5. Gametes are formed inside the RBC
6. Gametes are ingested in blood meal by tick

Question 8

What hosts can leishmania infect?

Answer 8

Humans, dogs, wild animals.

Question 9

How is leishmania transmitted?

Answer 9

Indirectly via sand fly vector.

Question 10

Where in the host does leishmania locate?

Answer 10

In macrophages where it replicates.

Question 11

What are the consequences of leishmania infection?

Answer 11

Skin ulcers, hair loss, eczema, fever, enlarged lymph nodes, death.

Question 12

How can leishmania be treated?

Answer 12

With drugs containing antimonial compounds.

Question 13

Describe the lifecycle of leishmania

Answer 13

1. Sandfly ingests blood meal from an infected host.
2. Asmatigotes that are ingested with the blood meal multiply by asexual reproduction.
3. They become promastigotes and migrate to the salivary gland of the sand fly.
4. Sand fly bites host and injects saliva, causing promastigotes to enter host blood stream.
5. Enter macrophages, become amastigotes which replicate by asexual reproduction.
6. Sandlfy ingests blood meal of infected host.

Question 14

What can be done to prevent leishmania infection?

Answer 14

Use of insecticides to kill sand flies. E.g. scalibor collar for dogs.

Question 15

Name a blood borne metazoan parasite

Answer 15

Heart worm (Dirofilaria immitis).

Question 16

Which species do heart worms infect?

Answer 16

Dogs, cats, ferrets, sealions.

Question 17

How are heart worms trasmitted?

Answer 17

Indirectly via a mosquito vector.

Question 18

Where in the host do heart worms locate?

Answer 18

Adults develop in the right artery of the heart and larvae (microfilaria) circulate in the blood.

Question 19

What are the effects of a heart worm infection?

Answer 19

Chronic cough, exercise intolerance, cardiovascular dysfunction.

Question 20

What can be used to treat heart worm?

Answer 20

Anthelmintic drugs, i.e. Ivermectin.

Question 21

What can be done to prevent heart worm infection?

Answer 21

Insecticides to kill the mosquitoes, e.g. scalibor collars.

Question 22

Describe the life cycle of the heart worm

Answer 22

1. Mosquito ingests a blood meal from an infected host.
2. Blood meal contains microfilariae which mature into infective juveniles which migrate to the salivary glands of the mosquitp.
3. Mosquito bites host and injects saliva containing juveniles.
4. Juveniles migrate to the right side of the heart and mature into males and females.
5. Female worm produce microfilariae which circulate in the blood.
6. Mosquito ingests blood meal.