Medical staff members carry a patient into Wuhan's Jinyintan hospital, where patients infected by the Wuhan coronavirus are being treated [Source: CNN]

Governments around the world have always struggled to stop the spread of disease, from the deadly swine flu which struck the globe in 2009, to ongoing attempts to rein in Ebola in West Africa.

No health authority has ever tackled the challenge currently faced by China, however, as the country grapples with a new coronavirus just as hundreds of millions prepare to travel during the Lunar New Year period — the largest annual human migration on Earth.

During the Lunar holiday, people from across the country will cram themselves into homebound trains, buses and planes for family reunions.

Others will take advantage of the time off to holiday overseas. Last year, close to 7 million Chinese tourists traveled abroad for Lunar New Year, according to state media.

The holiday — the most important in the Chinese calendar — comes at the worst possible time for health authorities racing to contain the outbreak of pneumonia which has put the rest of Asia on alert.

The virus, which was first identified in the central Chinese city of Wuhan, is known to have infected more than 200 people and spread to at least three other countries already.

On Monday, China’s National Health Commission confirmed that the Wuhan coronavirus can be passed from human-to-human and that medical staff had also been infected.

The disclosure followed news that South Korea had confirmed its first case, making it the third country outside of China to detect the virus.

The three cases previously confirmed overseas, two in Thailand and one in Japan, all involved people who had visited Wuhan.

“One of the consequences of a more connected world is that outbreaks have the potential to spread internationally much more rapidly than was the case 50 years ago,” said Mike Turner, director of science at the Wellcome Trust, a UK-based global health charity.

More cases have also been reported within China, evidence that the outbreak has spread well beyond Wuhan, creating a risk of unpredictable further infection.

As of Tuesday morning, five cases have been confirmed in Beijing, two in Shanghai, and 14 in the southern province of Guangdong — all hundreds of miles from Wuhan. Additional suspected cases have been reported across the country, from eastern Shandong province to Sichuan province in the southwest.

Chinese scientists on January 8 identified the pathogen as a new strain of coronavirus, the same family as severe acute respiratory syndrome (SARS).

In 2002 and 2003, SARS infected more than 8,000 people and killed 774 in a pandemic that ripped through Asia, spreading as far as Canada.