Malaria

Question 1

How does malaria get transmitted?

Answer 1

Parasite travels from mosquito (vector/host 1) to human (host 2) when sporozoites are delivered into human bloodstream through mosquito’s salivary glands

Question 2

Step 1

Answer 2

Malaria-infected Anopheles female inoculates/spreads sporozoites into human host during a blood meal (when she is drinking human’s blood)

Question 3

Step 2

Answer 3

Sporozoites infect human liver cells

Question 4

Step 3

Answer 4

Sporozoites mature into schizonts

Question 5

Step 4

Answer 5

Schizonts rupture and release merozoites

After initial replication in the liver, the parasites undergo asexual reproduction in the erythrocytes (erythrocytic schizogony)

Question 6

Step 5

Answer 6

Merozoites infect red blood cells (aka RBCs, aka erythrocytes)

Question 7

Step 6

Answer 7

Ring stage trophozoites mature into schizonts, which rupture to release merozoites

Question 8

Step 7

Answer 8

Some parasites differentiate into sexual erythrocytic stages (gametocytes)

Question 9

Step 8

Answer 9

The gametocytes, male (microgametocytes) and female (macrogametocytes), are ingested by an Anopheles mosquito during a blood meal

Blood-stage parasites are responsible for clinical manifestation of the disease

Parasites’ multiplication in the mosquito is called the sporogonic cycle

Question 10

Step 9

Answer 10

Within the mosquito’s stomach, the microgametes penetrate the macrogametes, thus fertilizing them and producing zygotes

Question 11

Step 10

Answer 11

Zygotes become mobile and elongated, forming into ookinetes

Question 12

Step 11

Answer 12

The ookinetes invade the midgut wall of the mosquito, where they develop into oocysts

Question 13

Step 12

Answer 13

Oocysts grow, rupture, and release sporozoites, which make their way to the salivary glands of the mosquito (begin the cycle again)