Safety Study of IV Peramivir in Hospitalized Subjects With Confirmed or Suspected Influenza

Inclusion Criteria: * Male and non-pregnant female subjects 6 years of age or older. * Able to provide written informed consent, or for whom written consent may be provided by a parent guardian or legally authorized representative, unless consent provided by a parent, guardian or legally authorized representative is not consistent with applicable local or ethical procedures, directives and /or guidelines. * Presence of clinical signs and/or symptoms consistent with an acute illness compatible with influenza infection; a measured temperature of ≥ 38.0°C (100.4°F) oral, or ≥ 38.6°C (101.4°F) rectal or tympanic and recent onset of at least one of the following: rhinorrhea or nasal congestion, sore throat or cough. Measured temperature can include fever meeting the above criteria as reported by the subject or their parent, guardian or legally authorized representative in the 24 hours prior to Screening. The requirement for fever is waived for any subject with influenza infection already confirmed by laboratory tests (including Rapid Antigen Tests). * Confirmation of influenza A or B infection in the local community by one of the following means: * the institution's local laboratory, * the local public health system * the national public health system * a laboratory of a recognized national or multinational influenza surveillance scheme. * Severity of illness requiring or anticipated to require in-hospital care. Exclusion Criteria: * Subjects who have been hospitalized for greater than 24 hours (not including time spent in the emergency department).Blood platelet count of \< 20 x 109/L. * Serum bilirubin \> 6 mg/dL at time of Screening evaluation. * Serum ALT or AST \> 5 X upper limit of normal at time of Screening evaluation. * Serum creatinine \> 5.0 mg/dL at time of Screening evaluation. * Subjects who require peritoneal dialysis or hemofiltration. * Altered neurologic status as defined by a Glasgow Coma Score of ≤ 9, unless medically induced. * Females who are pregnant (positive urine or serum pregnancy test at Screening evaluation) or breastfeeding. * Actively undergoing systemic chemotherapy or radiotherapy treatment for a malignancy. (Subjects who have completed treatment 30 days prior to enrollment are allowed to enroll in the study. Hormone treatment for cancer is also acceptable). * Prior hematopoietic stem cell transplantation or solid organ transplant during the previous 4 months. * HIV infection with a known CD4 count \< 200 cells/ mm3 unless on a stable highly active antiretroviral (HAART) regimen for at least 6 months. * Presence of a preexisting chronic infection that is undergoing or requiring medical therapy (eg, tuberculosis). (Subjects with chronic osteomyelitis or hepatitis B or C not requiring treatment are not excluded). * Presence of any preexisting illness that, in the opinion of the Investigator, would place the subject at an unreasonably increased risk through participation in this study. * Participation as a subject in any study of an experimental treatment for any condition within the 30 days prior to the time of the Screening evaluation. * Subjects diagnosed with cystic fibrosis. * Subjects with confirmed clinical evidence of acute non-influenzal infection at the time of Screening.