At least 40,000 have been infected by a new pathogen believed to have emerged late last year at a market in the central city of Wuhan.
In an attempt to contain the virus, cities in Hubei province at the epicentre of the outbreak have been locked down and many transport links countrywide have been cut to stop the movement of hundreds of millions of people who usually visit family during the annual Lunar New Year break. "When customers come in, we first take their temperature, then use disinfectant and ask them to wash their hands."
"I just checked and it would take 18 hours for me to go to work by bicycle," wrote one frustrated commuter on China's Twitter-like social media site Weibo. The death toll has overtaken global fatalities in the 2002-03 SARS epidemic when China drew international condemnation for covering up cases.