L3_Malaria & other blood borne parasitic infections. Flashcards
1
Q
Why do parasites benefit from invading RBCs?
A
- RBCs don’t have MHC class I on their surfaces, therefore they cant present antigens to the immune system.
2
Q
Which two categories can blood-borne infections get classed into?
A
- protozoan and helminth.
3
Q
What initiates the life-cycle of the plasmodium protist?
A
- when the mosquito takes a blood meal, this allows the parasite to undergo sexual reproduction in the mosquito.
4
Q
Briefly explain how a mosquito can infect an individual with malaria.
A
- when the mosquito carrying the parasite (plasmodium) takes a blood meal from a human, this allows the release of sporozoites into the individual.
- the sporozoites then enter the liver.
- in the liver, the sporozoites mature into schizonts, which eventually rupture and release merozoites.
- merozoites then infect RBCs.
- in the RBC, merozoites develop into trophozoites and give RBC the distinctive characteristic of an engagement ring.
- within the RBC, the plasmodium eats up the haemoglobin.
5
Q
Why is the liver a prime organ for parasites to inhabit?
A
- due to its reduced immune surveillance.
6
Q
How to diagnose malaria?
A
- blood stain under microscope.
- looking for double or single chromatin rings.
7
Q
What are malarial paroxysms?
A
- these are the periodic febrile attacks which affect the patient.
8
Q
Name two hallmarks of cerebral malaria.
A
- coma and seizures.
9
Q
How can malaria cause an oxygen starved environment in the brain?
A
- infected RBC will develop cell surface protrusions known as “knobs”.
- this limits the movement of the RBC towards the spleen and causes them to stick to the endothelial lining of the vessel.
- if this occludes the vessels leading to the brain, it can block the transport of oxygen to the brain, thus leading to seizures.
10
Q
Which drugs are available for the treatment of malaria?
A
- chloroquine, quinine, artemisinin.
