The North American countries affected by the swine flu - Canada, the USA and Mexico - have urged economic partners to continue trade. Agricultural ministers from the respective countries said the outbreak should not be a reason to restrict trade. Although the World Health Organisation has declared there is no evidence of the flu being transmitted through food, the North American pork industry is considered particularly vulnerable. Close to 20 nations have imposed bans on pig product imports from the three countries. Analysts have already assessed the economic impact of the outbreak with many stating that it could shatter a fragile global economic recovery, even outside of America. Banking multinational Credit Suisse said Asian economies with "sizeable tourism, retail and transportation sectors" such as Hong Kong, Malaysia, Singapore and Thailand would be most vulnerable to the economic fallout of swine flu.