With the death toll from the coronavirus at 1,017, the head of the World Health Organization gathered top scientists in Geneva on Tuesday to try and answer a raft of questions about the new disease.
Director-General Tedros Adhanom Ghebreyesus issued a plea for global unity against "a common enemy that does not respect borders or ideologies."
The WHO said there were 42,708 confirmed cases of the disease in China alone, with 393 more in 24 different countries. That includes a new case confirmed Monday in San Diego, the 13th person diagnosed in the U.S. Like most cases, that patient was recently in the Chinese city of Wuhan.
All but one of the fatalities from the virus have been in China.
"With 99% of cases in China, this remains very much an emergency for that country, but one that holds a very grave threat for the rest of the world," Tedros warned Tuesday, urging health officials and governments to "use the window of opportunity that we have now."
The WHO has grown increasingly concerned about the virus being transmitted from people with no recent history of travel to China to others in their home countries. Tedros said Monday that this "community spread," which has been seen now in the U.K. and Spain, at least, could be the "spark" that lights a bigger fire.