One of the persistent riddles of the deadly 1918 Spanish influenza pandemic is why it struck different cities with varying severity. Why were some municipalities such as St. Louis spared the fate of the hard-hit cities like Philadelphia when both implemented similar public health measures? What made the difference, according to two independent studies funded by the National Institutes of Health (NIH), was not only how but also how rapidly different cities responded.

Cities where public health officials imposed multiple social containment measures within a few days after the first local cases were recorded cut peak weekly death rates by up to half compared with cities that waited just a few weeks to respond. Overall mortality was also lower in cities that implemented early interventions, but the effect was smaller. These conclusions--the results of systematic analyses of historical data to determine the effectiveness of public health measures in 1918--are described in two articles published online this week in the journal Proceedings of the National Academy of Sciences.

These important papers suggest that a primary lesson of the 1918 influenza pandemic is that it is critical to intervene early, says Anthony S. Fauci, M.D., director of NIHs National Institute of Allergy and Infectious Diseases (NIAID), which funded one of the studies. While researchers are working very hard to develop pandemic influenza vaccines and increase the speed with which they can be made, nonpharmaceutical interventions may buy valuable time at the beginning of a pandemic while a targeted vaccine is being produced.

The historical analyses are part of an ongoing effort called the Models of Infectious Disease Agent Study (MIDAS), which is supported by NIHs National Institute of General Medical Sciences (NIGMS). Through MIDAS, researchers have developed computer models to examine how a future pandemic influenza virus might spread and what interventions could min
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Contact: Jason Socrates Bardi
jbardi@niaid.nih.gov
301-402-1663
NIH/National Institute of Allergy and Infectious Diseases
2-Apr-2007