[reureu]

^^ This is exactly the answer! The positive predictive value of a test changes based on the prevalence of the disease in the population. With rare conditions, you can end up with way more false positives than actual positives, which can cause actual harm to people.

"Outbreak" and "Contagion" both depict mass outbreaks of deadly viruses, and the social impacts of implementing last-ditch control efforts. There's a certain point where panic about an epidemic is more damaging than the epidemic itself, and I worry we're approaching that point with coronavirus. When everybody is freaking out is exactly when we need to enforce good public health practice, not throw it by the wayside and go full wild west.