[Clinical features in fatal Spanish influenza: Japanese Army Hospital medical records investigation].

Pandemic influenza preparedness requires a thorough knowledge of past pandemics. Tokyo First Army Hospital medical records from January 1918 to December 1920 found recently included 132 consecutive records of those diagnosed with influenza. We report on the clinical features in 8 fatal cases. Inpatient mortality was found to be 6.1% (8/132). Cough was noted in 6 (75%) and thoracic rales in 8 (100%) on admission, mimicking pneumonia. Bloody sputum was noted in 5 (62.5%) and diarrhea in 4 (50%), with marked hemorrhagic and digestive symptoms, resembling highly pathogenic avian influenza. Clinical features may differ from seasonal influenza, making early detection and treatment essential especially in severe cases.