Marsden P D, Bruce-Chwatt L J
Contemp Neurol Ser. 1975;12:29-44.
Cerebral malaria is an acute diffuse encephalopathy associated only with Plasmodium falciparum. It is probably a consequence of the rapid proliferation of the parasites in the body of man in relation to red cell invasion, and results in stagnation of blood flow in cerebralcapillaries with thromobotic occlusion of large numbers of cerebral capillaries. The subsequent cerebral pathology is cerebral infarction with haemorrhage and cerebral oedema. The wide prevalence of P. falciparum in highly endemic areas results in daily challenges to patients from several infected mosquitoes. It is thus important to understand the characteristics of P. falciparum, since this is one of the most important protozoan parasites of man and severe infection from it constitutes one of the few real clinical emergencies in tropical medicine. One of the more important aspects of the practice of medicine in the tropics is to establish a good understanding of the pattern of medical practice in that area. This applies to malaria as well as to other diseases. The neophyte might be somewhat surprised to learn, for example that an experienced colleague who lives in a holoendemic malarious area such as West Africa, sees no cerebral malaria. But the explanation is simple when the doctor concerned has a practice which involves treating adults only. Cerebral malaria is rare in adults, because in highly endemic areas, by the age of 1 year most of the infants in a group under study have already experienced their first falciparum infection. By the time they reach adult life, they have a solid immunity against severe falciparum infections. In fact, "clinical malaria" could occur in such a group under only two circumstances: 1) in pregnancy, a patent infection with P. falciparum might develop, probably due to an IgG drain across the placenta to the foetus;2) in an individual who has constantly taken antimalarials and who may have an immunity at such a low level that when antimalarial therapy is interrupted, clinical malaria might ensue. The above examples emphasise the paramount importance of the clinician dealing with malaria having some insight into the complex immunity processes operative in the human host; these have been reviewed by McGregor.
脑型疟疾是一种仅与恶性疟原虫相关的急性弥漫性脑病。它可能是由于寄生虫在人体中相对于红细胞入侵的快速增殖所致，导致脑毛细血管血流停滞，大量脑毛细血管血栓形成性阻塞。随后的脑部病理改变是伴有出血和脑水肿的脑梗死。在高度流行地区，恶性疟原虫广泛存在，导致患者每天都会受到几只感染蚊子的叮咬。因此，了解恶性疟原虫的特征非常重要，因为它是人类最重要的原生动物寄生虫之一，由其引起的严重感染是热带医学中为数不多的真正临床急症之一。热带地区医学实践中一个更重要的方面是要很好地了解该地区的医疗实践模式。这适用于疟疾以及其他疾病。例如，新手可能会有点惊讶地发现，一位生活在西非等高度流行疟疾地区的有经验的同事从未见过脑型疟疾。但当这位相关医生的业务只涉及治疗成年人时，解释就很简单了。脑型疟疾在成年人中很少见，因为在高度流行地区，到1岁时，研究中的大多数婴儿已经经历了首次恶性疟原虫感染。到他们成年时，他们对严重的恶性疟原虫感染具有稳固的免疫力。事实上，在这样一组人群中，“临床疟疾”可能仅在两种情况下发生：1）在怀孕期间，可能会发生恶性疟原虫的显性感染，这可能是由于IgG通过胎盘流向胎儿所致；2）在持续服用抗疟药且免疫力可能处于如此低水平的个体中，当抗疟治疗中断时，可能会发生临床疟疾。上述例子强调了治疗疟疾的临床医生对人类宿主中复杂免疫过程有一定了解的至关重要性；麦格雷戈对此进行了综述。
