The symptoms, which include chest pain, chills, a cough, headache and fever can emulate that of a cold, appearing more gradually than other types of pneumonia.

An outbreak of a mysterious virus has sickened hundreds of people in China, causing some deaths. Here's what we know about it.

The outbreak coincides with the country’s busiest travel period, as millions board trains and planes for the Lunar New Year holidays.

All of the cases so far have involved people either living in Wuhan or who have travelled to the city.

Officials at three U.S. airports will begin screening passengers from Wuhan, China, where a virus has caused an outbreak of pneumonia.

A second person has died in China of a mysterious virus, as more cases are reported in Thailand and Japan.

The WHO says no cases have been reported elsewhere in China or internationally.

While the United Nations health agency said it needed more comprehensive information to confirm precisely the type of pathogen causing the infections, it said a new coronavirus was a possibility.

More than 50 people have been isolated and are receiving treatment for an unexplained viral pneumonia in Wuhan, China.

With the newly reported cases, authorities believe a total of 15 patients in Hong Kong may have contracted a mysterious respiratory disease that has infected at least 44 people in the mainland Chinese city of Wuhan.