China sees deadliest day yet as global virus fears mounts China reported its biggest single-day jump in novel coronavirus deaths on Thursday, as confirmation that three Japanese evacuated from the outbreak's epicentre were infected deepened fears about a global contagion. The World Health Organization, which initially downplayed the severity of a disease that has now killed 170 nationwide, warned all governments to be "on alert" as it weighed whether to declare a global health emergency.