Malaria

Question 1

Malaria is transmitted from what insect?

Answer 1

Mosquito

Question 2

What is the parasite transmitted by mosquito that causes malaria?

Answer 2

Plasmodium

Question 3

What is the life cycle of Plasmodium?

Answer 3

Mosquito bites human and transmits sporozoites
Sporozoites travel from the blood to the liver
Hepatocytes are infected and sporozoites convert to merozoites
Merozoites replicate and transform into gametocytes
Gametocytes are taken up by the mosquito

Question 4

Mosquitoes transmit malaria much better in which endemic regions?

Answer 4

Tropical regions

Question 5

Which genetic polymorphism in some human genes protects against malaria?

Answer 5

Sickle cell anemia

Question 6

What causes sickle cell anemia?

Answer 6

Mutation in the hemoglobin gene

Question 7

Sickle cell hemoglobin forms what kind of chains in RBCs?

Answer 7

Long and inflexible chains

Question 8

What species of Plasmodium have human reservoir (stage 5 anthroponotic)?

Answer 8

Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malariae

Question 9

Which species of Plasmodium has monkey as the reservoir (stage 4 zoonotic)?

Answer 9

Plasmodium knowlesi

Question 10

Most cases of malaria are caused by which Plasmodium species

Answer 10

Plasmodium vivax and Plasmodium falciparum

Question 11

Most deaths are caused by which Plasmodium species?

Answer 11

Plasmodium falciparum

Question 12

What is the vaccination treatment for malaria?

Answer 12

RTS,S vaccine made of sporozoite surface protein (CSP)

Question 13

How many doses are required for the vaccination?

Answer 13

4 doses

Question 14

True or false: Vaccination provides great efficacy to treat severe malaria

Answer 14

False

Question 15

Chemotherapy for malaria includes which drugs?

Answer 15

Quinine, Chloroquine, Mefloquine and Artemisinin

Question 16

What treatment is recommended in chemotherapy to reduce development of drug resistance?

Answer 16

ACT (artemisinin combination therapy)

Question 17

Antimalaria drugs are recommended for whom?

Answer 17

All travelers to endemic areas, pregnant women living in Africa and infants 3-60 months old

Question 18

What is the vector control for malaria?

Answer 18

Pyrethroid insecticide-treated mosquito bed nets

Question 19

Why are there so many deaths in Africa from malaria?

Answer 19

Infrastructures are lacking, resources are limited for the amount of people that need them

Question 20

Which drugs inhibit merozoite mRNA translation?

Answer 20

Quinine and Mefloquine

Question 21

Which drugs inhibit hemozoin formation?

Answer 21

Chloroquine and Artemisinin

Question 22

How does hemozoin form?

Answer 22

Plasmodium breaks down hemoglobin and uses amino acids to form new parasites
Heme is crystallized to prevent parasite death

Question 23

What is the derivative of Quinine?

Answer 23

Chloroquine

Question 24

CSP binds to which protein from hepatocytes?

Answer 24

HSPG

Question 25

What is the signal for sporozoites to enter the liver?

Answer 25

HSPG and Kupffer cells

Question 26

What event starts the erythrocytic cycle?

Answer 26

Release of merozoites into bloodstream

Question 27

What is the precursor of merozoites?

Answer 27

Schizont

Question 28

What are important features of merozoites?

Answer 28

Dense granule, rhoptry, microneme

Question 29

Place the steps of merozoite entry into the RBC in order a. Merozoite is pushed into the RBC and replicates b. Merozoite reorients c. Merozoite adheres to the RBC d. RON2 from the RBC binds to AMA1 from the surface of merozoite

Answer 29

c, b, d, a

Question 30

How did malaria become a human disease from gorillas?

Answer 30

Gorilla RH5 merozoite surface protein mutated to bind to human CD147 on RBCs

Question 31

How can human mutations keep up with pathogen mutations?

Answer 31

Antibodies

Question 32

What are the stages of the erythrocyte cycle?

Answer 32

Merozoite enters the RBC, ring stage, trophozoite, schizont, merozoite replicates

Question 33

What protein is responsible for binding to endothelial cell receptors?

Answer 33

PfEMP1

Question 34

PfEMP1 protein is found on which cell?

Answer 34

Infected RBC

Question 35

How is P. falciparum prevented from entering the spleen?

Answer 35

PfEMP1 stops the RBC from entering the spleen

Question 36

Why does P. falciparum avoid the spleen?

Answer 36

Spleen macrophages destroy infected RBCs

Question 37

True or false: All tissues have the same PfEMP1 proteins

Answer 37

False

Question 38

Which structure do PfEMP1 proteins bind to?

Answer 38

Glycoproteins

Question 39

True or false: Pathology is different depending on where PfEMP1 binds in the body

Answer 39

True

Question 40

Which events are caused by PfEMP1 mediated RBC binding?

Answer 40

Rosetting and endothelial cytoadherence

Question 41

True or false: Rosetting and endothelial cytoadherence lead to vascular obstruction, which contributes to hypoxia

Answer 41

True

Question 42

Hypoxia causes which of the following? a. Anemia b. Metabolic alkalosis c. Cerebral malaria

Answer 42

a and c

Question 43

Why are antibodies not able to neutralize PfEMP1 surface proteins?

Answer 43

They block the receptors that bind to the endothelial cells

Question 44

True or false: Every Var gene is the same

Answer 44

False

Question 45

How many Var genes are expressed at a time within the entire population?

Answer 45

One

Question 46

Who are most susceptible to malaria?

Answer 46

Infants under the age of 5

Question 47

Why are older people less susceptible to get malaria?

Answer 47

Antibodies build up and promote the development of asymptomatic infections

Question 48

What is naturally acquired immunity maintained by repeated exposure from infective mosquito bites?

Answer 48

Premunition

Question 49

Which merozoite surface protein binds to blood group antigens A and B?

Answer 49

RIFIN

Question 50

Which merozoite surface protein binds to glycophorin C as an anchor?

Answer 50

STEVOR

Question 51

What is the role of RIFIN?

Answer 51

Binds to LILLRB1 and inhibits NK and B cells

Question 52

What is the role of STEVOR?

Answer 52

Stimulates rosetting between infected and non-infected RBCs