The majority of the 675 000 individuals who died during the 1918-1919 influenza outbreak likely died from secondary bacterial pneumonia rather than infection with the H1N1 strain of the influenza virus alone, according to scientists from the National Institute of Allergy and Infectious Diseases.
In an examination of postmortem tissue samples from 58 individuals who perished during the outbreak, the scientists consistently found evidence of severe bacterial pneumonia (Morens DM et al. J Infect Dis. doi:10.1086 /591708 [published online ahead of print August 18, 2008]). Additionally, they reviewed published accounts of 8398 autopsies and found that the bacteriological and histological findings suggested secondary bacterial pneumonia was the ultimate cause of death.
Kuehn BM. Pandemic Planning. JAMA. 2008;300(12):1403. doi:10.1001/jama.300.12.1403-b