Flu Didn't Kill Most in 1918

(August 21, 2008) - Scientists now believe it wasn't influenza (Read about "Influenza") that killed most people during the great 1918 flu pandemic. Now they believe that normal bacteria (Read about "Microorganisms") we all carry ran wild when people's immune systems (Read about "The Immune System") were compromised by the flu.

The majority of deaths during the influenza pandemic of 1918-1919 were not caused by the influenza virus acting alone, report researchers from the National Institute of Allergy and Infectious Diseases (NIAID). Instead, most victims succumbed to bacterial pneumonia (link to i26) following influenza virus infection. The pneumonia was caused when bacteria that normally inhabit the nose and throat invaded the lungs along a pathway created when the virus destroyed the cells that line the bronchial tubes and lungs. (Read about "Respiratory System")

A future influenza pandemic may unfold in a similar manner, say the NIAID authors, whose paper in the Journal of Infectious Diseases is now available online. Therefore, the authors conclude, comprehensive pandemic preparations should include not only efforts to produce new or improved influenza vaccines and antiviral drugs but also provisions to stockpile antibiotics and bacterial vaccines as well.

The work presents complementary lines of evidence from the fields of pathology and history of medicine to support this conclusion. "The weight of evidence we examined from both historical and modern analyses of the 1918 influenza pandemic favors a scenario in which viral damage followed by bacterial pneumonia led to the vast majority of deaths," says co-author NIAID Director Anthony S. Fauci, M.D. "In essence, the virus landed the first blow while bacteria delivered the knockout punch."