Plasmodium vivax

Plasmodium vivax

Plasmodium vivax is a protozoal parasite and a human pathogen. The most frequent and widely distributed cause of recurring (Malaria tertiana) malaria, P. vivax is one of the five species of malaria parasites that commonly infect humans. It is less virulent than Plasmodium falciparum, the deadliest of the five, but vivax malaria can lead to severe disease and death due to splenomegaly (a pathologically enlarged spleen). It also afflicts people with conditions such as anemia and malnutrition.

Plasmodium vivax

Life Cycle

The life cycle of P. vivax involves two hosts, humans and female Anopheles mosquitoes. The parasites grow and multiply first in the liver cells and then in the red cells of the blood in humans. In the mosquito, they multiply in the gut, then invade the salivary glands of the mosquito.

Symptoms

The symptoms of P. vivax infection include fever, chills, nausea, flu-like illness, and in severe cases, anemia and respiratory distress. The periodicity of symptoms corresponds to the life-cycle of the parasite in the red blood cells and is every third day for P. vivax.

Microphotographs of Plasmodium vivax in Giemsa-stained thin blood films

Treatment

The treatment of P. vivax malaria is a two-step process, which includes treatment for the acute infection and then treatment for the prevention of relapse. The drugs of choice for the treatment of P. vivax malaria are chloroquine and primaquine.

Prevention

Prevention of P. vivax involves reducing mosquito population and human contact with mosquitoes. This is done by using insecticide-treated nets, indoor residual spraying, and larvicides.

See Also

• Malaria
• Plasmodium falciparum
• Anopheles mosquito
• Protozoa