The World Health Organisation's (WHO) director-general will convene an emergency meeting on Wednesday to discuss the mysterious coronavirus spreading across Asia.
On Tuesday, China's National Health Commission confirmed the virus, that has killed at least three people and infected 217 in China, could spread by human-to-human transmission. About 139 new cases were reported over the weekend.
"Now we can say it is certain that it is a human-to-human transmission phenomenon," Zhong Nanshan, the scientist leading the expert panel on the oubreak, said. Two cases reported in Guangdong are believed to have come from human transmission. Medical staff there are also infected.
Following that announcement, Tedros Adhanom Ghebreyesus, WHO's director-general said an urgent meeting would be held to ascertain whether the "outbreak constitutes a public health emergency of international concern and what recommendations should be made to manage it".
Most cases of the virus (which is officially called 2019 - nCoV) are in the city of Wuhan, but the respiratory illness has also been detected in centres like Shanghai and Beijing. Other countries, like Japan, South Korea and Thailand, are also reporting cases.
The virus is believed to belong to the same group of coronaviruses as the Severe Acute Respiratory Syndrome (SARS), which killed nearly 800 people globally in a 2002-2003 outbreak. That illness also began in China.
However, little is known about the illness. There is currently no vaccine for it. Officials are now trying to understand how efficiently the virus can spread to understand its potential threat.
Previously, WHO said the most likely source of the mystery virus outbreak was an animal source, but experts said there were too many cases to rule out human-to-human transmission.
There are also concerns about the spread of the virus as China enters its busiest travel season with the start of the Chinese New Year. About 400 million people travel domestically and internationally during that period.
"Our commission will step up our guard during the Spring Festival, pay close attention to the development and change of the epidemic, and direct the implementation of prevention and control measures," the National Health Commission said on Monday.
Airports in China, the United States and Canada have begun screening passengers from Wuhan. However, WHO is yet to recommend any restriction to trade or travel.
"Countries are encouraged to continue strengthening their preparedness for health emergencies in line with the International Health Regulations (2005)."
WHO was first informed of cases of the virus in Wuhan on December 31. It was identified as a coronavirus on January 7.
"Common signs of infection include respiratory symptoms, fever, cough, shortness of breath and breathing difficulties. In more severe cases, infection can cause pneumonia, severe acute respiratory syndrome, kidney failure and even death," WHO says.
"Standard recommendations to prevent infection spread include regular hand washing, covering mouth and nose when coughing and sneezing, thoroughly cooking meat and eggs. Avoid close contact with anyone showing symptoms of respiratory illness such as coughing and sneezing."
