To start the cycle, an infected female Anopheles mosquito injects sporozoites into the skin while feeding.

Repeated cycles cause illness and potential death if not treated.

Sporozoites enter the blood stream and are carried to the liver, where they infect liver cells.

Within liver cells, the parasites develop into schizonts.

In some malaria species, parasites remain in the liver, causing relapses.

The schizonts rupture, releasing thousands of individual merozo-ites into the bloodstream.

Merozoites infect red blood cells.

The male gamete fuses with the female gamete producing a zygote.

The zygotes elongate into ookinetes which move through the stomach wall.

The ookinetes develop into oocysts.

The oocysts grow and rupture, releasing sporozoites.

The sporozoites migrate to the salivary glands, ready to be injected and renew the cycle.

LIVERCELL

INFECTEDLIVER CELL

INFECTED CELL(DORMANT)

SCHIZONT

SCHIZONT

RUPTURED SCHIZONT

TROPHOZOITE

INFECTEDRED BLOODCELL

RINGSTAGE

MEROZOITES

GAMETOCYTES

GAMETES

OOKINETE

STOMACHWALL

ZYGOTE

SALIVARY GLANDS

OOCYST

SPOROZOITES

SPOROZOITES

1

1

2

2

3

3

4

4

5

5

Some parasites change into male and female forms called gametocytes.

6

7

7

8

9

10

11

12

13

9

8

11

10

12

13

The Carter Center / Graphic by Al Granberg

The Life Cycle of Malaria

When the mosquito feeds, gametocytes are ingested into its stomach.

The gametocytes emerge from the infected blood cells, becoming gametes.

GAMETOCYTES

BLOOD CELL

An infected mosquitostarts the cycle

Another mosquitobecomes infected,

continuing the cycle

SPOROZOITE

BLOOD CELL

MOSQUITO STAGES(7-10 days)

HUMAN BLOOD STAGESCAUSE ILLNESS

(2-3 day cycles)

HUMAN LIVER STAGES(About 2 weeks)