Following the 1957 influenza A pandemic, a number of communications emphasizing the pulmonary complications of this infection appeared.1,2 As expected, a great increase in the incidence of bacterial pneumonia occurred. Most of these pneumonias did not pose the threat they did during the 1918-1919 pandemic because they could be effectively treated with antimicrobial agents. In their place severe primary influenza virus pneumonia appeared as the most dreaded influenzal complication. Goodpasture was the first to clearly ascribe fatal pneumonia to the influenza "virus" in 1919.3 Scattered reports subsequently appeared,4,5 but the existence of influenza virus pneumonia was not emphasized until the study by Louria et al during the 1957 pandemic.1 In that study six patients with severe bilateral pneumonia felt to be due to the influenza virus were described. All patients had underlying heart disease, and four had rheumatic heart disease. Five of the six died.
In