MSCI's broadest index of Asia-Pacific shares outside Japan dipped 0.2 per cent, and Tokyo's Nikkei shed 1.3 per cent.
Hong Kong streets were calm early on Thursday as while police largely kept their distance from tens of thousands of mostly young people who have continued protests for nearly a week.
US stocks dropped more than 1 per cent on Wednesday as the Ebola news scared investors, economic data pointed to uneven growth, and the Russell 2000 index of small-cap shares entered correction territory.
Investors warmed to the Japanese currency after a slew of surveys showed German factory activity shrank for the first time in 15 months, China's manufacturing sector barely grew, while the United States slowed more than expected.
The dollar traded at 109.025 yen, suffering a sharp fall on declining US Treasury yields after poking above the psychological 110 threshold the previous day for the first time since 2008.
The euro stood little changed at $1.2628 after crawling away from a two-year low of $1.2571 hit earlier in the week.
The European Central Bank meeting later in the session was in focus with the divergence of US and European monetary policies now a well-established set market theme.
The US Federal Reserve is probing ways to normalise monetary policy, while the ECB is seen stuck with its very lose easy policy for the foreseeable future.
"The market interest is not in the rates decision, where the ECB insists the refinancing rate will not fall further from 0.05 per cent, but in President Draghi's press conference," Sean Callow, senior currency strategist at Westpac in Sydney, wrote in a note to clients.
The markets will focus on the expected size of the ECB's plan to buy asset-backed securities and euro-denominated covered bonds after Draghi promised to provide "detailed modalities" of the plans at the previous meeting in September, Callow said.
In commodities, crude oil posted a modest rebound after declining sharply through much of the week on weak economic signals from China and Europe and ample global supply.
US crude, which on Tuesday clocked its biggest one-day fall since November 2012 and still hovered near a 16-month low of $90.43 hit last month, rose 18 cents to $90.91 a barrel.
Gold extended gains after rising overnight as the tumble in Wall Street prompted safe haven bids, with a steadying dollar and weakness in global equities also supporting the precious metal.
Spot gold rose 0.15 per cent to $1,215.10 an ounce.
Copyright: Thomson Reuters 2014