Plasmodium vivax is a protozoan parasite that causes malaria, primarily in tropical and subtropical regions. It is one of the five species of the genus Plasmodium that infect humans. This parasite is known for its ability to remain dormant in the liver, leading to relapses of malaria symptoms even after initial treatment. Transmission occurs through the bite of infected female Anopheles mosquitoes. Symptoms of P. vivax malaria include fever, chills, and fatigue, typically appearing 10 to 17 days after infection. Effective treatment involves antimalarial medications, and prevention focuses on mosquito control and personal protection measures.