The world economy may be heading for its worst performance since the financial crisis, more than a decade ago, as the spread of new virus that causes COVID-19 increasingly dashes hopes of a swift rebound.

A few weeks ago most economists bet the China-led slump would quickly reverse once the virus was contained, but many are now rethinking that optimism as swaths of Chinese factories remain shut and workers idle. Having already severed supply chains and undermined tourism and trade, outbreaks from Europe to the Americas threaten activity elsewhere too.

Bank of America Corp. economists warned clients Thursday that they now expect 2.8 percent global growth this year, the weakest since 2009. They were already penciling in the softest growth in China since 1990, but now say the U.S. will expand the least in four years.