( CNN ) -- More than a week after the swine flu outbreak rattled the world , with cases of infected people popping up from Mexico to South Korea , the new virus strain has shown up in a herd of swine . Masked workers push food to a sealed-off hotel in Beijing where Mexican nationals are being quarantined . The catch , Canadian officials say , is that the animals may have caught the flu from a human . Canadian officials are quarantining pigs that tested positive for the virus -- scientifically known as 2009 H1N1 -- at an Alberta farm in what could be the first identified case of pigs infected during the recent outbreak . They said the pigs may have been infected by a Canadian farmer who recently returned from a trip to Mexico , the epicenter of the outbreak that has sickened more than 680 people . The farmer `` may have exposed swine on the farm to an influenza virus , '' said Dr. Brian Evans of the Canadian Food Inspection Agency . `` We have determined that the virus H1N1 , found in these pigs , is the virus which is being tracked in the human population , '' he added . Learn about the virus » . Evans and other officials said it is not uncommon for flu viruses to jump from humans to animals and that it does not pose a risk for consuming pork . The number of pigs infected was not disclosed . The infected farmer had flu-like symptoms and is recovering , Evans said . Meanwhile , as the number of confirmed swine flu cases reached 787 worldwide , the World Health Organization said Sunday it had started distributing 2.4 million doses of a common anti-viral drug to 72 nations . So far , 17 countries have confirmed cases of swine flu , the WHO said . Watch latest developments as swine flu sweeps world » . Dr. Michael J. Ryan , the WHO director of its global alert and response team , said the doses of the drug Tamiflu came from a stockpile that was donated by Swiss health-care giant Roche in 2005 and 2006 . Roche said it was working with the WHO to prepare for the virus . The drug should be taken within 48 hours of experiencing symptoms , according to the drug 's Web site . Mexico has the most confirmed swine flu cases , with 506 infected people and 16 deaths , the WHO said . Mexican Health Minister Jose Angel Cordova Villalobos reported that the country has confirmed 421 cases and 19 deaths . Several other countries , including Canada and Italy , had confirmed additional cases that had not yet been added to the WHO 's total . The United States has the second-highest number of confirmed cases , with 160 sickened and one death , according to the Centers for Disease Control and Prevention and the WHO . President Barack Obama spoke with Mexican President Felipe Calderon on Saturday afternoon to discuss both countries ' `` efforts to limit the spread of the 2009 H1N1 flu strain and the importance of close U.S.-Mexican cooperation , '' the White House said in a statement . Other than Mexico and the United States , the WHO confirmed cases in 14 other countries : Canada , with 70 ; the United Kingdom with 15 ; Spain with 13 ; Germany with six ; New Zealand with four ; Israel with three ; France , with two ; and Austria , China , South Korea , Denmark , the Netherlands , Switzerland and Costa Rica , each have one . See where cases have been confirmed » . Ryan said the WHO was still preparing for a pandemic . `` At this point we have to expect that phase six will be reached , '' he said , referring to the organization 's highest pandemic threat level . `` We have to hope that it is not reached . '' And he noted that a pandemic describes `` the geographic spread of the disease , not its severity . '' The latest developments come as parts of Asia discovered they were not immune to the spread of the virus . Hundreds of guests and staff were under quarantine in China after health officials determined that a hotel guest had contracted the H1N1 virus . Nearly 200 hotel guests and 100 staff members were ordered to stay in Metro Park Hotel in Hong Kong for seven days to stop the spread of the H1N1 virus , a government spokesman said . The quarantine was ordered after a 25-year-old Mexican man stayed in the hotel and became sick , according to the spokesman . It is the first confirmed case of the virus in Hong Kong , local medical officials said . South Korean officials on Saturday confirmed their first case -- a 51-year-old nun who recently traveled to Mexico for volunteer work .
Pigs in Canada may be first in recent outbreak to test positive for virus . One - third of 160 sick Americans visited Mexico or had contact with Mexico . WHO reports 37 confirmed cases of H1N1 infection in 15 countries .