Dayananda Kiran K, Achur Rajeshwara N, Gowda D Channe
Department of Biochemistry, K.S. Hegde Medical Academy, NITTE University, Mangaluru, Karnataka, India.
Department of Biochemistry, Kuvempu University, Shankaraghatta, Karnataka, India.
J Vector Borne Dis. 2018 Jan-Mar;55(1):1-8. doi: 10.4103/0972-9062.234620.
Malaria, caused by the protozoan parasites of the genus Plasmodium, is a major health problem in many countries of the world. Five parasite species namely, Plasmodium falciparum, P. vivax, P. malariae, P. ovale, and P. knowlesi, cause malaria in humans. Of these, P. falciparum and P. vivax are the most prevalent and account for the majority of the global malaria cases. In most areas of Africa, P. vivax infection is essentially absent because of the inherited lack of Duffy antigen receptor for chemokines on the surface of red blood cells that is involved in the parasite invasion of erythrocytes. Therefore, in Africa, most malaria infections are by P. falciparum and the highest burden of P. vivax infection is in Southeast Asia and South America. Plasmodium falciparum is the most virulent and as such, it is responsible for the majority of malarial mortality, particularly in Africa. Although, P. vivax infection has long been considered to be benign, recent studies have reported life-threatening consequences, including acute respiratory distress syndrome, cerebral malaria, multi-organ failure, dyserythropoiesis and anaemia. Despite exhibiting low parasite biomass in infected people due to parasite's specificity to infect only reticulocytes, P. vivax infection triggers higher inflammatory responses and exacerbated clinical symptoms than P. falciparum, such as fever and chills. Another characteristic feature of P. vivax infection, compared to P. falciparum infection, is persistence of the parasite as dormant liver-stage hypnozoites, causing recurrent episodes of malaria. This review article summarizes the published information on P. vivax epidemiology, drug resistance and pathophysiology.
疟疾由疟原虫属的原生动物寄生虫引起，是世界上许多国家的主要健康问题。有五种寄生虫物种，即恶性疟原虫、间日疟原虫、三日疟原虫、卵形疟原虫和诺氏疟原虫可导致人类疟疾。其中，恶性疟原虫和间日疟原虫最为普遍，占全球疟疾病例的大多数。在非洲的大多数地区，由于红细胞表面缺乏参与寄生虫侵入红细胞的趋化因子达菲抗原受体，基本不存在间日疟原虫感染。因此，在非洲，大多数疟疾感染是由恶性疟原虫引起的，间日疟原虫感染的最高负担在东南亚和南美洲。恶性疟原虫毒性最强，因此它是导致大多数疟疾死亡的原因，尤其是在非洲。尽管长期以来间日疟原虫感染被认为是良性的，但最近的研究报告了危及生命的后果，包括急性呼吸窘迫综合征、脑型疟疾、多器官衰竭、红细胞生成异常和贫血。尽管由于寄生虫仅感染网织红细胞的特异性，感染人群中的寄生虫生物量较低，但与恶性疟原虫相比，间日疟原虫感染引发的炎症反应更高，临床症状更严重，如发热和寒战。与恶性疟原虫感染相比，间日疟原虫感染的另一个特征是寄生虫以休眠的肝期潜隐子形式持续存在，导致疟疾反复发作。这篇综述文章总结了已发表的关于间日疟原虫流行病学、耐药性和病理生理学的信息。
