"I am declaring a public health emergency of worldwide concern over the global outbreak of 2019nCoV, not because of what is happening in China, but because of what is happening in other countries", announced Tedros Adhanom Ghebreyesus, WHO Director General.
Concern about the new virus has mushroomed around the world as more cases turn up outside China.
The CDC says the relatively few people who have been identified as close contacts of people with confirmed coronavirus infections should follow the guidance of their doctors and health departments. More than 200 deaths and almost 10,000 cases have been reported in China, the vast majority in and around Wuhan, China, where it is believed to have originated in a market that traded in illegal wildlife.
Earlier today, the first human to human transmission of coronavirus in the us was confirmed.
China's United Nations ambassador, Zhang Jun, said Beijing was assessing the declaration. "Our greatest concern is the potential for this virus to spread to countries with weaker health systems which are ill-prepared to deal with it".
"Let me be clear: this declaration is not a vote of no confidence in China", Tedros reiterated at the press conference announcing the PHEIC. The announcement also imposes more disease reporting requirements on countries.
Ghebreyesus stressed that at this time, World Health Organization is not recommending any trade or travel in response to the outbreak. "We don't know what sort of damage the virus could do if it were to spread in a country with [a] weaker health system", Ghebreyesus said. Many countries ramp up their security provisions at airports and limit Chinese arrivals in a bid to curb the spread of the unsafe outbreak, while also attempting expeditiously to evacuate tourists from the virus-hit territories.
People returning from Wuhan and other areas of high-risk in China should be vigilant for signs of illness, including fever and cough, according to the CDC. It had been de facto closed because of the Lunar New Year holiday, but Russian authorities said the closure would be extended until March 1.
The first five known USA patients are believed to have contracted the virus during visits to China, epicenter of the worldwide outbreak, whereas the newly diagnosed IL patient - confirmed by the CDC on Wednesday - was infected by his wife.
Almost all of the cases at this point are from people who have traveled to the Chinese city of Wuhan.
The case in South Korea was a 56-year-old man who had contact with a patient who was diagnosed with the new virus earlier.
"The main reason for this declaration is not because of what is happening in China but because of what is happening in other countries".
The sample of the student, who had returned from China recently, was confirmed positive by the National Institute of Virology, Pune.
"We anticipated this", said Dr. William Schaffner, a Vanderbilt University infectious diseases expert. Officials said the virus probably initially spread from animals to people, as did SARS and MERS.
"If transmission between humans was hard, then the numbers would have plateaued", he said.
That means the small city-state has the second highest number of cases outside of mainland China, behind Thailand, which has 14 confirmed cases.
Novel coronavirus belongs to the coronavirus family that causes illnesses ranging from the common cold to acute respiratory syndromes. Of the new deaths, 37 were in Hubei province, of which Wuhan is the capital, and one was in the southwestern province of Sichuan.
That stands in stark contrast to the initial response to SARS, when medical reports were hidden as state secrets.