疟疾(malaria)
由原生动物疟原虫属）引起的复发性的严重原虫病，由按蚊属（参阅mosquitoes）的多种蚊虫叮咬传染人。从西元前5世纪起就为人所知，主要在热带和亚热带接近沼泽的地方发生。直到20世纪初期确定了蚊虫和寄生虫在本病中所起的作用。20世纪晚期，年度发病例估计在2.5亿，其中200万人死亡。不同的疟原虫传播的疟疾在发病程度、死亡率和地区分布上不同。寄生虫有一个极复杂的生活史：其中一个步骤同红血球的生长同时进行。它们每间隔48或72小时分裂一次，造成4至10小时的痛苦。病人可能会战栗和感到寒冷，体温上升到40.6℃，并伴有严重的头疼，在体温降回正常时会大量出汗。病人常常会产生贫血、脾肿大和全身虚弱等症状。并发症可致命。在血液中寻找寄生虫可诊断疟疾。奎宁久被用来消退发热。合成药，如氯（chloroquine），可以杀死红血球中的寄生虫，但很多寄生虫现已有抗药性。携带有血红蛋白病基因对疟疾具有天然免疫力。疟疾的预防需要清除蚊虫的滋生地，并用杀虫剂或天敌补食、纱窗和纱网以及驱虫剂。
English version：
malaria
Protozoal disease, a serious, relapsing infection caused by protozoa of the genus Plasmodium (see plasmodium), transmitted by the bite of Anopheles mosquitoes. Known since before the 5th century BC, it occurs in tropical and subtropical regions near swamps. The roles of the mosquito and the parasite were not proven until the early 20th century. Annual cases worldwide are estimated at 250 million and deaths at 2 million. Malaria from different Plasmodium species differs in severity, mortality, and geographic distribution. The parasites have an extremely complex life cycle; in one stage they develop synchronously inside red blood cells. Their mass fissions at 48- or 72-hour intervals cause attacks lasting 4-10 hours. Shaking and chills are followed by fever of up to 105°F (40.6°C), with severe headache, and then profuse sweating as temperature returns to normal. Patients often have anemia, spleen enlargement, and general weakness. Complications can be fatal. Malaria is diagnosed by detecting the parasites in blood. Quinine was long used to alleviate the fevers. Synthetic drugs, such as chloroquine, destroy the parasites in blood cells, but many strains are now resistant. Carriers of a gene for a hemoglobinopathy have natural resistance. Malaria prevention requires preventing mosquito bites by eliminating mosquito breeding places and using insecticides or natural predators, window screens, netting, and insect repellent.