Malaria

Question 1

Vector of malaria

Answer 1

Anopheles mosquito

Question 2

Malaria life cycle

Answer 2

1. Pre-erythrocytic stage
   a. Mosquito injects sporozoites to the blood
   b. Sporozoites invade liver to undergo asexual reproduction
   c. Sporozoites produce merozoites (merogony)
   d. Liver cells burst and merozoites spill out to the blood = symptoms
2. Asexual intraerythrocytic stage
   a. Merozoites invade RBCs
   b. Merozoites become trophozoites and multiply
   c. Once trophozoites consumed 2/3 of RBC’s hemoglobin, they produce schizonts (schizogony)
   d. RBCs burst and schizonts spill out to the blood
   e. Cycle repeat
3. Sporogony
   a. Some develop into gametocytes
   b. Mosquito ingest gametocytes from blood
   c. Male and female gametocytes produce a zygote
   d. Zygote matures into an ookinete
   e. Ookinete matures into an oocyst
   f. Oocyst matures into a sporozoite
   g. Bursts to spill out sporozoites
   h. Sporozoites migrate into the salivary gland of the mosquito

Question 3

When is sporogony not completed

Answer 3

At cooler temperatures

Question 4

Malaria pigment

Answer 4

Hemozoin = produced when hemoglobin is consumed by the parasite and heme is detoxified

Question 5

Predilection for young RBCs

Answer 5

P. vivax and P. ovale

Question 6

Predilection for old RBCs

Answer 6

P. malariae

Question 7

Can invade RBCs of all ages and sequesters into other organs

Answer 7

P. falciparum

Question 8

Manifestations of severe falciparum malaria

Answer 8

1. Unarousable to noxious stimuli, coma persisting >30 min after generalized convulsions
2. pH <7.25, HCO3 <15, lactate >15
3. Hct <15, hgb <5 with parasitemia >100,000
4. Oliguria, crea >3
5. Noncardiogenic pulmonary edema
6. Glucose <40
7. Severe hemorrhage, DIC
8. SBP <80, core/skin temp difference >10
9. > 2 generalized seizures in 24hrs
10. Black, brown or red urine
11. Obtunded but arousable
12. Parasitemia >5 in nonimmune patients
13. Bilirubin >3

Question 9

Best biochemical prognosticators in severe malaria

Answer 9

Bicarbonate and lactate levels

Question 10

Bacteremia associated with P. falciparum infections in endemic areas

Answer 10

Salmonella bacteremia

Question 11

Stage in life cycle of malaria not present with transfusion malaria

Answer 11

Preerythrocytic stage so no hypnozoite

Question 12

Complication of tropical splenomegaly

Answer 12

Malignant lymphoproliferative disorder

Question 13

Pattern of deposits in quartan malarial nephropathy with better prognosis

Answer 13

IgG3 deposits with selective proteinuria has better prognosis than IgG2 deposits with nonselective proteinuria

Question 14

Associated lymphoma in malaria

Answer 14

Burkitt lymphoma secondary to EBV infection

Question 15

Diagnosis of malaria

Answer 15

Peripheral blood smear showing asexual forms of the parasite

Question 16

Treatment of choice for nonfalciparum malaria

Answer 16

Choloroquine

Question 17

First line treatment for falciparum malaria endemic areas

Answer 17

Artemisinin based

Question 18

First line treatment for severe malaria

Answer 18

Artesunate

Question 19

Radical treatment for vivax and ovale

Answer 19

Primaquine for 14 days

**if pregnant: chloroquine until delivery then primaquine

Question 20

Chemoprophylaxis for pregnant women

Answer 20

Mefloquine

Question 21

Chemoprophylaxis for malaria

Answer 21

Chloroquine: only for chloroquine-sensitive P. falciparum or P. vivax
The rest: atovaquone/proguanil (malarone), doxycyline, mefloquine

Question 22

Antimalarial that can cause hypoglycemia

Answer 22

Quinidine and quinine

Question 23

Antimalarial that can cause cinchonism

Answer 23

Quinine and quinidine

Question 24

Antimalarial that can cause massive hemolysis in G6PD patients

Answer 24

Primaquine