The United States has declared a national public health emergency over the coronavirus outbreak, as the US Centres for Disease Control and Prevention has quarantined 195 Americans who were evacuated from Wuhan, China.

“The United States government will implement temporary measures to increase our abilities to detect and contain the coronavirus proactively and aggressively,” said Health and Human Services secretary Alex Azar, during a press conference in the White House.

The decision to raise that alarm came just hours after those 195 people were evacuated, in an a rare mandatory order for Americans that has not been issued in more than 50 years.

The disease, so far, has spread to 10,000 people globally, and has been confirmed in patients in a growing number of countries that now include the US, Canada, the UK, Italy, France, Germany, Australia, Sweden, Finland, Japan and India, among other countries.

“While we recognise this is an unprecedented action, we are facing an unprecedented public health threat,” said Dr Nancy Messonnier, the director for the National Centre for Immunisation and Respiratory Diseases, in a conference call on Friday.

The emergency declaration followed after the Pentagon issued travel guidelines for US troops and civilians living abroad, hoping to help Americans choosing to evacuate from areas impacted by the virus.

“We’re aware of the concerns. The safety of our service members, civilian employees, and our citizens both here and abroad is of the utmost concern,” said Army Lt Col Dave Eastburn, in a statement emailed to CNBC.

In the US, six people have tested positive for the virus, while another 235 have been tested (114 have come up negative).