By Bhavan Jaipragas

The United States will deny entry to foreigners travelling from mainland China to prevent the new coronavirus from spreading after declaring a public health emergency on Friday.

President Donald Trump’s order will require US citizens, permanent residents and immediate family members arriving in the country from China’s Hubei province – the epicentre of the contagion – to be quarantined for 14 days starting Sunday at 5:00pm Eastern time.

The measures were announced by the White House task force on the coronavirus led by Health and Human Services Secretary Alex Azar. The order came as US health authorities confirmed the seventh case of the contagion – officially known as the 2019 novel coronavirus – in Santa Clara, California.

The move by Washington follows similar restrictions put in place by Japan and Singapore on incoming visitors from mainland China.

The two Asian countries moved to close their borders to residents of the mainland after the World Health Organisation’s declaration of a global health emergency on Thursday.

“Foreign nationals, other than immediate family of US citizens and permanent residents, who have travelled in China within the last 14 days will be denied entry into the United States for this time,” said Azar.

“The actions we have taken and continue to take, complement … the work of China and the World Health Organisation to contain the outbreak within China,” he said.

All US citizens, permanent residents and immediate family members travelling from other parts of China will be subject to “proactive entry screening” and self-quarantine for 14 days.

The US will also funnel all flights from China to seven airports: New York’s John F. Kennedy, Chicago’s O’Hare, San Francisco, Seattle, Atlanta, Honolulu and LAX in Los Angeles.

Officials from the Centres for Disease Control and Prevention (CDC), among the members of the task force, emphasised that the measures were taken out of abundance of caution because of “unknowns” surrounding how the disease is spreading outside of China.

“The issue now with this is that there is a lot of unknowns,” said Anthony Fauci, director of the CDC’s National Institute of Allergy and Infectious Diseases.

“In the beginning we were not sure there were asymptomatic infections, which would make it a much broader outbreak than we are seeing. Now we know that there are,” he added.

Asked why the administration was taking these measures despite its repeated emphasis that the virus posed a low risk in the US, Azar said he hoped that “people will see that their government is taking responsible steps to protect them”.

“These are preventive steps, the risk is low in the United States,” he said.

Apart from CDC officials, the task force led by Azar includes representatives from the National Institutes of Health, the Department of Homeland Security, the Transportation Department and the Department of State.

Joel Szabat, the Acting Under Secretary for Policy, Department for Transportation, said in the briefing that Friday’s measures did not constitute a “travel ban” on China.

Szabat however noted that the three US airlines that fly to China -- Delta Air Lines, United Airlines and American Airlines -- had all temporarily suspended flights to and from the mainland even before the measures were announced.

“We will be working going forward with the US and Chinese passenger airlines about their flight plans going forward,” he said.

Earlier on Friday, the CDC announced a mandatory quarantine of 195 Americans evacuated from Wuhan earlier this week. It was the first such directive issued in some five decades.

As of Friday, more than 9,800 people have been infected in China with over 130 cases reported in 26 countries or territories, including Taiwan.

All 213 deaths caused by the virus have occurred in China.

The case in Santa Clara is the first in the San Francisco Bay area and the third in California.