The U.S. has declared a public health emergency and will temporarily bar entry to the U.S. of foreign nationals believed to be a risk of transmitting the virus. In addition, Americans returning from the centre of the outbreak will be required to undergo 14 days of mandatory quarantine. Americans returning from mainland China will be allowed to self-monitor their condition for a similar two-week period. These restrictions take effect Sunday evening at 5 p.m.

Meantime, U.S. health officials have issued a quarantine order for all 195 American evacuees from China. It’s the first time in 50 years that Washington has taken such a step. The evacuees will spend two weeks at a military base in California.

As nervousness over the new virus grips the world, at least two Central American countries say they’ll turn back visitors who’ve recently gone to China; Guatemala and El Salvador. There are no confirmed cases in Latin America.

China’s ambassador in Geneva says the World Health Organization’s decision to declare a global emergency was warranted but cautions against ”unnecessary panic” or ”excessive measures” in response.