If a particular infection seems like an obvious cause, then a test for that might be used, like the Western blot for Borrelia burgdorferi bacteria, or a thin blood smear for malaria.

如果特定的感染原似乎是明显病因，那么一个测试很可能被使用，像对莱姆病螺旋菌采取的西方墨点法，或者对疟疾脑膜炎症采取的薄血涂片法。