Largest outbreak was in Mexico which had 156 confirmed cases . The virus had spread to 11 countries , with western hemisphere hardest hit . Mexico suspects 150 deaths have been caused by H1N1 virus . Comment:
Largest outbreak was in Mexico which had 156 confirmed cases . The virus had spread to 11 countries , with western hemisphere hardest hit . Mexico suspects 150 deaths have been caused by H1N1 virus . U.S. and Mexico the only countries showing human-to-human spread so far .