As many as 5.7 million Americans were infected with swine flu during the first few months of the pandemic, according to estimates from federal health officials. Scientists at the Centers for Disease Control and Prevention estimate that between 1.8 million and 5.7 million Americans were infected from mid-April through July 23. The figures are the CDC's most specific calculation to date. They also estimated that between 9,000 and 21,000 hospitalizations occurred during that time. The estimates are in a CDC publication, Emerging Infectious Diseases, and were posted on the journal's website this week. To come up with the numbers, the scientists assumed that most people infected with swine flu had only mild illnesses and did not get medical care or get tested. For every confirmed case, they estimated that probably 80 others occurred. And for every confirmed hospitalization, there were probably three others.
