1. Medical uncertainty. More than any other aspect of the pathogen and the disease it causes, uncertainties instill a deep sense of dread. The uncertainties include who is most at risk of infection or severe illness (or death), who can spread it, what protective steps are warranted (is hand-washing and staying away from indoor crowds sufficient, or should you not leave your home?), and how the outbreak will unfold. It is the uncertainty that drives us crazy! 2. Unfamiliarit