Plasmodium & Malaria

Question 1

What transmits malaria

Answer 1

FEMALE anopheles mosquito’s depositing eggs in stagnating water, saliva contains anticoagulant to prevent clotting

Question 2

Name the 5 types of malaria and what they are

Answer 2

Falciparum - subtertiana
Ovale - tertiana
Vivax - tertiana
Malaria - quartana
Knowles - quotidiana

Question 3

Describe the life cycle of malaria

Answer 3

1) Takes a blood meal injecting sporozoites
2) Enters liver through kupffer cells into hepatocyte where they replicate
3) schizont divides and ruptures (kills hepatocyte)
4) enters blood stream, merozoites infect RBC’s
5) Trophozoite grows in cell and doesn’t divide or goes through erythrotic cycle
6) small number become sexually active - gametocyte
7) Mosquito takes a blood meal, gametocytes
8) enters sporogonic cycle, microgamete enters macrogamete
9) Ookinete, oocyst ruptures releasing sporozoites

Question 4

Describe these symptoms

1) Liver stage
2) Anaemia
3) Splenomegaly
4) Jaundice

Answer 4

1) no symptoms in liver cells
2) losing red blood cells
3) dead red blood cells are stored in spleen
4) impaired liver function

Question 5

What causes malaria fever

Answer 5

host cytokines (IL-6) released in response to pyrogens
tertiana - 48
quartana - 72
subtertiana - sort of 48

Question 6

How does malaria cause

1) Hypoglycaemia
2) Anaemia
3) Acidosis

Answer 6

1) Cytokine-induced impairment of gluconeogenesis in the liver and glucose consumption by parasite.
2) Destruction of RBCs when schizonts rupture, haemolysis and cytokines affect erythropoiesis in bone marrow
3) Tissue anoxia leads to anaerobic metabolism and lactic acid

Question 7

Describe these terms

1) recrudescence
2) reinfection
3) relapse

Answer 7

1) malaria is caused by a small number of permitting parasites
2) new inoculation of parasites
3) hypnozoites in liver are reactivated

Question 8

What are the effects of a HIV/Malaria Co-infection

Answer 8

CD4+ counts progressively decrease so become more susceptible to malaria, higher parasitaemia and viral load

Question 9

What is the duffy factor

Answer 9

Duffy antigen/chemokine receptor (DARC/CD234)

Glycoprotein on the surface of blood cells used by vivid merozoites for invasion

Question 10

What is sickle cell disease

Answer 10

single point mutation (GAG-GTG) resulting in one amino acid B globulin molecule causing b-globulin to form long stacks distorting shape of RBC

Question 11

What is thalassaemia

Answer 11

Genetic disorder affecting haemoglobin synthesis, one or two genes on chromosome 16 are affected

Question 12

What is the role of Glucose - 6 - phosphate DH

Answer 12

Rte limiting enzyme in pentose phosphate pathway, needed for regeneration of NADPH vital for reduction of glutathione (anti-oxidant) Eryptosis
x-chromosome linked