A New Disease Is Testing Us for the Next Global Epidemic

The World Health Organization released its yearly list of infectious diseases that its experts think are especially high-risk. This year’s specimen included the pathogens that public health people consider the usual deadly suspects: Ebola and other hemorrhagic fevers, MERS and SARS, and mosquito-borne Zika and Rift Valley Fever. But there was also a novel entry: Disease X.