Malaria

Question 1

What are the two main types of malaria?

Answer 1

P. falciparum and P. vivax

Question 2

Where is P. falciparum worst in the world?

Answer 2

sub saharan Africa

Question 3

Where is P. vivax the worst?

Answer 3

asia pacific and south and central america

Question 4

What are the obstacles to combating malaria?

Answer 4

no vaccine, drug resistance, insecticide resistance, plus economic, social and political factors

Question 5

Which type of malaria causes the most severe type of malaria?

Answer 5

P. falciparum

Question 6

Which type of malaria has a dormant liver stage?

Answer 6

P. vivax

Question 7

What transmits malaria?

Answer 7

female anopheles mosquitos

Question 8

How long does P. falciparum incubate in the liver for?

Answer 8

7-10 days

Question 9

During what stage of the life cycle does malaria cause disease?

Answer 9

when there are high numbers of parasites in the blood stream - the liver stage is asymptomatic

Question 10

What are sporozoites?

Answer 10

the stage of the life cycle that infects the human

Question 11

What are merozoites?

Answer 11

the stage of the life cycle that infects the blood stream

Question 12

What does the immune response target?

Answer 12

merozoites

Question 13

What are the clinical features of uncomplicated (mild) malaria?

Answer 13

flu like illness with fever, headache, malaise

Question 14

What are the clinical features of severe malaria

Answer 14

severe anaemia, cerebral malaria (coma, convulsions), respiratory distress and metabolic acidsosis, hypoglycaemia, kidney failure, blood clotting problems

Question 15

What percentage of cases are severe malaria?

Answer 15

5%

Question 16

What is the treatment of mild malaria?

Answer 16

short course of anti malarials

Question 17

What is the treatment of mild malaria caused by P.vivax

Answer 17

14 day course of anti malarials - because of the doormant liver stage

Question 18

What is the treatment of severe malaria?

Answer 18

anti malarials and supportive care

Question 19

What causes the problems in the body from malaria?

Answer 19

parasites accumulating in vital organs, inflammatory response, destruction of RBCs

Question 20

What are the three types of immunity to malaria?

Answer 20

immunity that prevents severe malaria, immunity that prevents any malaria and immunity that protects against malaria in pregnancy

Question 21

Why is there slow develop of immunity to malaria?

Answer 21

multiple antigenic targets, antigenic diversity, antigenic variation

Question 22

What genetic factors help in resistance to malaria?

Answer 22

sickle cell, alpha-thalassemia, blood groups

Question 23

What acquired immune response is there against sporozoites?

Answer 23

antibodies and T cells - the antibodies prevent infection of hepatocytes

Question 24

What acquired immune response is there against infected hepatocytes?

Answer 24

T cells

Question 25

What acquired immune response is there against merozoites?

Answer 25

antibodies - inhibit invasion of RBCs

Question 26

What acquired immune response is there against infected RBCs?

Answer 26

antibodies (because parasite antigens are expressed on the cell surface) and CD4 T cells

Question 27

Which cytokine in the blood stage is associated with protection?

Answer 27

IFNgamma

Question 28

Which cytokine in the blood stage is associated with severe disease?

Answer 28

TNFalpha

Question 29

What are the different types of vaccines against malaria?

Answer 29

vaccines that target sporozoites, vaccines that target merozoites or vaccines that target the sexual stages to stop transmission

Question 30

What is the RTS,S vaccine?

Answer 30

a vaccine which targets the major antigen on sporozoites

Question 31

What is the efficacy of the RTS,S vaccine and how long does it last?

Answer 31

30-50% and only lasts 2 years

Question 32

Why is it difficult to develop a vaccine that targets merozoites?

Answer 32

because there are so many different antigens

Question 33

Are there vaccines available for P. vivax?

Answer 33

no