"Certain populations appear to be at elevated risk
of severe outcomes, including Native American groups.
American Indians and Alaska natives historically are at high risk
for severe respiratory infections; while it is unclear what toll
they have suffered from 2009-H1N1, a cluster of severe 2009-H1N1
disease among First Nation people in remote Manitoba, Canada,
suggests that these groups may be at high risk. Cases of
2009-H1N1 virus infection in these clusters have had rapidly
progressive, diffuse, lower airway disease (compared to seasonal
influenza, which more commonly involves the upper airway), resulting
in development of acute respiratory distress syndrome (ARDS) and
prolonged ICU admission."