This virus is a strange one. Apparently there's no single symptom that affects even a small majority of the infected patients. That's a strange, unusual problem

This virus is a strange one. Apparently there's no single symptom that affects even a small majority of the infected patients. That's a strange, unusual problem to handle for a system that assumes that illnesses make people ill. A hospital is self-selecting, in that it doesn't have 50% patients that feel well and show no symptoms. The people who work at a hospital take the precautions that are considered appropriate for the disease they've diagnosed. This means that to some degree, they're not ambushed by asymptomatic infected people.