The swine flu outbreak could shatter fragile signs of a global economic rebound, but the gravity of its impact depends on the death toll it inflicts and the panic it generates, analysts said.
For Asia, where some countries are in recession, the crisis has revived memories of the severe acute respiratory syndrome (SARS) outbreak in 2003 that killed hundreds, halted travel and sent economies reeling.
Asia's first case of the A(H1N1) virus was confirmed in Hong Kong Friday, the epicentre of the 2003 SARS outbreak when close to 300 people died.
"The global economy faces yet another huge challenge," research firm Moody's Economy.Com said in a market analysis.
"The recent outbreak of swine flu in Mexico and its rapid spread to other countries could interrupt trade and investment, exacerbating the worldwide recession for an uncertain period."
The World Health Organisation has raised its flu alert level to five out of six, signalling a pandemic was "imminent" as more nations announced cases.
"The risk here is if swine flu is actually more lethal than SARS and containment measures are not effective," Leong Wai Ho, a Singapore-based regional economist with Barclays Capital, told AFP.