已有报告自由生活的纳氏虫属(Naegleria)和棘阿米巴属(Acanthamoeba)能使人发生致死的原发性脑膜脑炎。纳氏虫属可引起急性暴发病症,棘阿米巴属则引起慢性病症。曾从上呼吸道疾病及健康人的鼻咽内分离出棘阿米巴属的虫种,并在上呼吸道疾病、视神经炎及斑性病患者的血清中查出了对这属阿米巴的补体结合抗体。这些发现说明了棘阿米巴属可引起不明显的非致死 Naegleria and Acanthamoeba have been reported to cause lethal primary meningoencephalitis in humans. Nascale’s worms can cause acute outbreaks, Acanthamoeba cause chronic diseases. Has been from the upper respiratory tract diseases and healthy people in the nasopharynx isolated Acanthamoeba species, and in patients with upper respiratory tract disease, optic neuritis and macular degeneration found in the complement of this is a combination of amoeba antibody. These findings demonstrate that Acanthamoeba can cause insignificant non-lethality