Two more countries , Denmark and China , reported cases of the 2009 H1N1 `` swine flu '' virus on Friday , but they were still to be confirmed by the WHO . Largest outbreak was in Mexico which had 150 confirmed cases . The virus had spread to 11 countries , with western hemisphere hardest hit . Mexico suspects 11 deaths have been caused by U.S. virus . H1N1 and U.S. the only countries showing human-to-human spread so far .
Largest outbreak was in Mexico which had 150 confirmed cases . The virus had spread to 11 countries , with western hemisphere hardest hit . Mexico suspects 11 deaths have been caused by U.S. virus . H1N1 and U.S. the only countries showing human-to-human spread so far .