Three countries worst hit by the global swine flu outbreak have urged economic partners not to allow it to affect international trade.

受全球性猪流感爆发影响最大的三个国家呼吁其贸易伙伴不要因此影响到国际贸易。

There is no evidence of swine flu being transmitted through food.

Agricultural ministers from Canada, Mexico and the US said the outbreak should not be used as a reason for unnecessary trade restrictions¹.

North America's pork industry is seen as especially vulnerable（易受伤害的，有弱点的）.

But the World Health Organization has insisted there is no evidence of the virus being transmitted through food.

Almost 20 nations, including China and Russia, have imposed bans on the importation of pigs and pork products from Canada, the US and Mexico.

Asia impact

Separately, analysts² at Moody's Economy.com said that the outbreak could shatter（打碎，破掉） fragile goings of a global economic recovery.

"The outbreak in Mexico and its rapid spread to other countries could interrupt trade and investment, exacerbating³（加重） the worldwide recession for an uncertain period."

Meanwhile, at the annual meeting of the Asian Development Bank, the organisation's acting⁴ chief economist⁵, Jong-Wha Lee said Asian trade and tourism could be hit by the outbreak.

But he said that its lessons learned form the 2003 Sars epidemic⁶ would help it counter its effects.

Swiss banking⁷ giant Credit Suisse said that, in Asia, economies with "sizeable（相当打的） tourism, retail⁸（零售） and transportation sectors⁹" such as Hong Kong, Malaysia, Singapore and Thailand would be most vulnerable to the economic fall-out of swine flu.