Uncertainty over the swine-flu outbreak cast a shadow over the struggling global economy Monday, raising fears that that the spread of the virus could harm trade and tourism and undermine businesses just as they begin to rally. Airline stocks plummeted as major travel companies in Europe and Asia cancelled tours to Mexico, the epicenter of the outbreak. Pharmaceutical companies rallied on expectations that demand for antiviral drugs may surge to deal with any pandemic. It's far from clear how bad the outbreak will be, but any blow to travel and trade could eat away further at world gross domestic product, already forecast by the International Monetary Fund to shrink 1.3 percent this year in the first decline since World War II. Top finance officials meeting in Washington over the weekend said recovery could emerge by the end of the year. "On top of a synchronized global financial and economic crisis, an outbreak of swine fever is the last thing we need just now," said Neil Mackinnon, chief economist at ECU Group. The virus is suspected in up to 103 deaths and 1,600 more cases in Mexico, while 40 cases were confirmed in the United States and six in Canada. Both Swiss drugmaker Roche Holding AG, the maker of Tamiflu, and GlaxoSmithkline PLC, which manufactures the Relenza drug, rose 4 percent in European trading. Gilead Sciences Inc., which developed Tamiflu and receives royalties from Roche, rose 4%. Not all countries have significant stockpiles of the Tamiflu and Relenza. It will take months for pharmaceutical companies to produce a vaccine, starting from a seed virus. Businesses went over their crisis plans and weighed up the potential lost productivity if the virus spreads and workforces are crippled. London-based risk-management company Business Forums International said its phones ran hot on Monday as hundreds of companies made inquiries about contingency plans to deal with the absenteeism that that could come if the outbreak turns into a worldwide pandemic. BFI program manager Elizabeth Smith said many businesses were better prepared since the bird-flu scare in early 2006 put pandemic risks higher on their agenda; the group has held 20 conferences in the past three years involving some 10,000 businesses across Europe, albeit focused on fears of a bird-flu, rather than swine-flu, outbreak. Meanwhile, tourism operators across Asia and Europe canceled tours to Mexico after EU health officials urged Europeans on Monday to postpone nonessential travel to the United States and Mexico. TUI Travel, Europe's biggest tour operator, said it was suspending all trips to Mexico City through May 4. Japan's largest tour agency JTB Corp. has suspended Mexico tours until at least June 30. Irina Tyurina, a spokeswoman for the Association of Russian Travel Agencies, said about 30% of people booked to travel to Mexico in early May had canceled their plans. She said Russian travel agencies were in talks with their Mexican counterparts to receive refunds for hotels and services.