The swine-flu threat is not over. The Washington Post reports that scientists have been monitoring outbreaks in Australia, New Zealand, Argentina, South Africa and other countries, where the virus disproportionately affects young people. Since popping up last spring in Mexico, the virus has sickened at least 162,000 people in at least 168 countries, killing at least 1,154. According to U.S. and international health officials, a new round of the H1N1 virus, which spread during the Southern Hemisphere's winter, could hit the Northern Hemisphere within weeks, leading to major disruptions in schools, workplaces and hospitals. North American officials are on top of it, though. Barack Obama flew to Guadalajara on Sunday to meet with Mexican President Felipe Calderon and Canadian Prime Minister Stephen Harper in a two-day summit that will likely produce a joint plan of attack for swine flu.