Historic Pandemic

Predominant Role of Bacterial Pneumonia as a Cause of Death in Pandemic Influenza: Implications for Pandemic Influenza Preparedness

The Journal of Infectious Diseases, Volume 198, Issue 7, 1 October 2008, Pages 962–970

David M. Morens, Jeffery K. Taubenberger, and Anthony S. Fauci

Methods

Prior to the use of antibiotics

1918 –1919 “Spanish flu” (H1N1) pandemic, 675,000 excess US deaths

(1.9 million on current population figures)

Examined lung tissue sections

Obtained during 58 autopsies

Reviewed pathologic and bacteriologic data from 109 published autopsy series

that described 8,398 individual autopsy investigations.

Results

Uniformly exhibited severe changes indicative of bacterial pneumonia

Bacteria, neutrophils, blood

Bacteriologic and histopathologic results clearly and consistently implicated secondary bacterial pneumonia

Caused by common upper respiratory tract bacteria in most influenza fatalities

Many different bacterial strains

Blood cultures, 1,887 subjects (table 2)

Positive results in 70.3% of cases, typically contained either pneumococci or streptococci

Conclusions

The majority of deaths in the 1918–1919 influenza pandemic likely resulted directly from secondary bacterial pneumonia…

caused by common upper respiratory–tract bacteria

Viral-bacterial copathogenesis

Prevention, diagnosis, prophylaxis, and treatment of secondary bacterial pneumonia

Stockpiling of antibiotics and bacterial vaccines

Less substantial data from subsequent pandemics

1957 H2N2 Asian flu, 86,000 excess US deaths

1968 H3N2 Hong Kong flu, 56,300 excess US deaths

The extraordinary severity of the 1918 pandemic remains un- explained