The United States announced Friday it would be taking new measures to combat a coronavirus outbreak, including denying entry to foreign nationals who had recently visited China and imposing 14-day quarantines on American citizens returning from mainland China.

More than 11,800 people have been diagnosed with the rapidly spreading virus. More than 250 have died, all of them in China. The State Department told Americans not to travel there and advised those who are already there to consider leaving.

Following a quarantine order issued Friday, which government officials said was last used in the 1960s, evacuees held at a base in California will have their movements tightly controlled for 14 days after they left China because health experts are still uncertain about how readily the virus spreads.

Here is what we know:

●The United States has issued a “Level 4” travel advisory for China, its highest level of caution, over the rapidly spreading outbreak.

●Beginning Sunday, the United States will funnel all flights from China to the United States through seven airports.

●Americans returning to the United States who have been in China’s Hubei province within 14 days will face a mandatory quarantine. Americans returning to the United States from other parts of China will face enhanced screening and a self-quarantine of up to 14 days.

●The World Health Organization has declared the virus a global public health emergency, requiring states to ramp up their responses.

●Are you in isolation or quarantine because of the coronavirus? We want to hear your story.