Blood borne parasites Flashcards
Name 2 examples of blood borne protozoan parasites
Babesia and leishmania.
What hosts can babesia infect?
Cattle, dogs, horses, sheep, pigs and humans.
How is babesia trasmitted?
Indirectly via tick vector.
Where in the host does babesia parasite locate?
Erythrocytes, where it replicates.
What are the consequences of babesia infection?
Severe haemolytic anaemia; up to 75% of RBC are destroyed.
How can babesiosis be treated?
With Imidocarb or aracacides to kill the tick infestation.
Describe the lifecyle of babesia
- Tick ingests infected hosts blood. RBC’s contain gametes that replicate by sexual reproduction.
- Sporozoites form and migrate to the salivary glands of the tick.
- Tick bites host and injects saliva causing the sporozoites to enter vertebrate host blood stream.
- Sporozoites enter RBC and multiply by asexual reproduction to form merozoites.
- Gametes are formed inside the RBC
- Gametes are ingested in blood meal by tick
What hosts can leishmania infect?
Humans, dogs, wild animals.
How is leishmania transmitted?
Indirectly via sand fly vector.
Where in the host does leishmania locate?
In macrophages where it replicates.
What are the consequences of leishmania infection?
Skin ulcers, hair loss, eczema, fever, enlarged lymph nodes, death.
How can leishmania be treated?
With drugs containing antimonial compounds.
Describe the lifecycle of leishmania
- Sandfly ingests blood meal from an infected host.
- Asmatigotes that are ingested with the blood meal multiply by asexual reproduction.
- They become promastigotes and migrate to the salivary gland of the sand fly.
- Sand fly bites host and injects saliva, causing promastigotes to enter host blood stream.
- Enter macrophages, become amastigotes which replicate by asexual reproduction.
- Sandlfy ingests blood meal of infected host.
What can be done to prevent leishmania infection?
Use of insecticides to kill sand flies. E.g. scalibor collar for dogs.
Name a blood borne metazoan parasite
Heart worm (Dirofilaria immitis).
Which species do heart worms infect?
Dogs, cats, ferrets, sealions.
How are heart worms trasmitted?
Indirectly via a mosquito vector.
Where in the host do heart worms locate?
Adults develop in the right artery of the heart and larvae (microfilaria) circulate in the blood.
What are the effects of a heart worm infection?
Chronic cough, exercise intolerance, cardiovascular dysfunction.
What can be used to treat heart worm?
Anthelmintic drugs, i.e. Ivermectin.
What can be done to prevent heart worm infection?
Insecticides to kill the mosquitoes, e.g. scalibor collars.
Describe the life cycle of the heart worm
- Mosquito ingests a blood meal from an infected host.
- Blood meal contains microfilariae which mature into infective juveniles which migrate to the salivary glands of the mosquitp.
- Mosquito bites host and injects saliva containing juveniles.
- Juveniles migrate to the right side of the heart and mature into males and females.
- Female worm produce microfilariae which circulate in the blood.
- Mosquito ingests blood meal.
