The International Monetary Fund's managing director, Kristalina Georgieva, said in a blog post this week that the organization expects a severe drop in China's first quarter economic growth, but "only a small reduction for the entire year" if the spread of the virus is quickly contained.

A longer lasting and more severe outbreak will result in a sharper slowdown, with "more substantial supply chain disruptions and a more persistent drop in investor confidence," she warned.

If the coronavirus outbreak becomes a global pandemic, $1 trillion could be wiped off the world economy, with recessions in the United States and the eurozone, according to economists at Oxford Economics. A pandemic limited to Asia would knock some $400 billion off global GDP in 2020.

For now, demand around the world is "holding up quite well," while measures to contain the virus in China appear to be working, giving companies reason to be optimistic, said John Stopford, head of multi-asset income at Investec Asset Management.

"The consensus view is that these kinds of shocks tend to have a short-term impact but then most of that is recovered," he told CNN Business.

At the same time, prolonged shutdowns in China or an increase in cases outside the country could cause longer term disruption, Stopford said. "The longer it goes on, the incrementally worse the consequences become. If Chinese production is out for two quarters rather than one, the impact on businesses will be much more material."

The response of the Chinese government is another unknown. It has already stepped in to cushion the blow to the domestic economy through fiscal stimulus and subsidies, and may step up measures to contain the fallout.