Before the 2009 H1N1 swine flu came along, planners were preparing for a deadly disease with a case/fatality ratio of 0.1% -- that is, for one death in every 1,000 symptomatic infections.The team now calculates that the H1N1 swine flu has a case/fatality ratio no higher than 0.048% and maybe six to eight times lower, depending on the methods used for calculation.