The World Health Organization on Thursday declared the outbreak of a novel coronavirus a global health emergency, an acknowledgement of the risk the virus poses to countries beyond its origin in China and of the need for a more coordinated international response to the outbreak.WHO Director-General Tedros Adhanom Ghebreyesus made the announcement following a meeting of the WHO’s emergency committee. Last week, the committee had recommended that a public health emergency of international concern, or PHEIC, not be declared yet because of limited spread of the virus outside of China.Tedros reconvened the committee this week because some other countries, including Japan, Germany, Vietnam, and, as of Thursday, the United States, had reported limited human-to-human transmission of the virus — a warning sign that the virus could start circulating more broadly outside China.