Life Cycle of the Malaria Parasite
Malaria
Malaria is caused by single-cell parasites of genus Plasmodium (P.). Four types of P. parasites infect humans: Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, and Plasmodium malariae. Among these P. falciparum is the most common and most deadly. Malaria parasites develop through various stages of its life cycle in two hosts Anopheles mosquitoes and humans. Anopheles mosquitoes are found worldwide except in Antarctica. Many Anopheles species transmit the parasites that cause malaria in humans. The parasite's life cycle is complex and multi-layered, which has presented many challenges in eradicating the disease. Each year an estimated 500 million people suffer from malaria worldwide, and over 1 million people die from it.
Life cycle in human
1. Malaria-infected female Anopheles mosquito injects its saliva with sporozoites into a person while taking a blood meal.
2. Sporozoites infect liver cells.
3. Merozoites emerge from infected liver cells to infect and multiply in red blood cells.
4a. Infected red blood cells release more merozoites that infect more red blood cells.
4b. Gametocytes develop in some merozoite-infected red blood cells and produce male and female sex cells.
5. A female Anopheles mosquito ingests malaria-infected blood including gametocytes.
Life cycle in mosquito
6. Male sperm fertilizes female egg.
7. Sporozoites from oocyst migrate to salivary gland where they mature.
8. Malaria-infected female Anopheles mosquito injects its saliva with sporozoites into a person while taking a blood meal.