translation.en: They didn't know what they were dealing with, and to make it even more complicated, the virus itself was causing a symptom, a type of a presentation that wasn't classical of the disease.
translation.zh: 他们不知道自己面对的是什么， 而令事情更为复杂的是， 病毒本身引起了一种症状， 一种这种病非典型的表现。