 Groups of 16 subjects receive an intravenous infusion of peramivir 12 subject or placebo 4 subjects once a day for 5 consecutive days. The first four infusions are given in the NIH outpatient clinic. The dose of peramivir is increased in successive groups of 16 subjects as long as the preceding dose was well tolerated. Before the infusion on day 1, subjects have a physical examination, blood test and EKG to obtain baseline values. After the infusion, they remain in the hospital for 6 hours. Vital signs and symptoms are c... 