Selected hematology at time of admission by age group in influenza A H1N1pdm confirmed fatalities (excluding patients with influenza A H1N1pdm nosocomial infections unless otherwise reported), Argentina, June 15–July 31, 2009.

**Lymphopenia was defined as <3000 cells/ml for patients under 5 years old, <2000 cells/ml for patients 5-12 years old and <1,500 cells/ml for patients over 12 years old.
††Anemia was defined as less than 11 g/dl of hemoglobin (Hb) for patients less than 5 years old and for pregnant women (>15 years old), less than 11.5 g/dl Hb for patients 5–12 years old, less than 12 g/dl Hb for patients 12–15 years old and for non-pregnant women (>15 years old), and less than 13 g/dl Hb for men 15 years and older.
§§“Acidosis or hypoxemia” is defined as pH under 7.36 or oxygen saturation less than 96%.