疟疾（Malaria)是世界六大热带病和我国五大寄生虫病之一，对人类危害极大，非洲每年死于malaria的儿童约100万。malaria主要分布在热带、亚热带各国，在我国华南、华中的某些地区，特别是云南和海南省尚有不少病例，因此，malaria仍是我国重点防治的寄生虫病之一。
疟原虫属原生动物亚界--顶复门--孢子纲--疟原虫属。
寄生虫人体的疟原虫有四种：间日疟原虫、恶性疟原虫、三日疟原虫和卵形疟原虫。
疟原虫经蚊叮咬感染人后引起malaria，典型临床表现是周期性寒战、发热和出汗。
诊断主要靠外周血涂片检查。
间日疟原虫用磷酸氯喹及磷酸伯氨喹治疗，恶性疟原虫用氯喹，对抗氯喹株则宜用青蒿素类药物、奎宁、咯萘啶、磺胺多辛和乙胺嘧啶等联合用药。
形态：
子孢子
红外期裂殖体
Pre-erythrocytic schizont in liver.
These mature in 6-14 days’ time liberation merozoites into the blood stream. Giemsa-colophonium. ×400. Enlarged by 5.4.
环状体
P. vivax thin smear, showing early trophozoites.
The infected red cells are enlarged and show some stippling. Giemsa. ×1000. Enlarged by 5.4.
P. vivax thick smear, early trophozoites.
The red cells are lysed. Giemsa. ×1000. Enlarged by 5.4.
成熟滋养体
P.vivax thin smear.
Showing late trophozoites (amoeboid stage). The infected red cells are enlarged and show marked stippling. Giemsa. ×1000. Enlarged by 5.4.
裂殖体
P. vivax thin smear.
A mature schizont about to rupture. A clump of malarial pigment can be seen in the center. Giemsa. ×1000. Enlarged by 5.4.
P. vivax thin smear.
Merozoites lying free. Malarial pigment is seen as a clump on one side. Giemsa. ×1000. Enlarged by 5.4.
间日疟原虫雄配子体
间日疟原虫雌配子体
