Malaria
Malaria, debilitating infectious disease characterized by chills, shaking, and periodic bouts of intense fever . Caused by single-celled parasites of the genus Plasmodium, malaria is transmitted from person to person by the bite of female mosquitoes . Malaria in humans is caused by four species of Plasmodium parasites. Plasmodium falciparum is the most common species in tropical areas and is transmitted primarily during the rainy season. This species is the most dangerous, accounting for half of all clinical cases of malaria and 90 percent of deaths from the disease. Plasmodium vivax is the most widely distributed parasite, existing in temperate as well as tropical climates. Plasmodium malariae can also be found in temperate and tropical climates but is less common than Plasmodium vivax. Plasmodium ovale is a relatively rare parasite, restricted to tropical climates and found primarily in eastern Africa. The fever that characterizes malaria develops when merozoites invade and destroy r...