In the summer of 2005, the Center for the History of Medicine at the University of Michigan Medical School was contacted by the Defense Threat Reduction Agency (DTRA) and asked to conduct research into and write a report on American communities that had experienced extremely low rates of influenza during the infamous 1918-1920 influenza pandemic. A team of historians from the Center for the History of Medicine visited these communities to locate, assess, and collect available primary source material from libraries, archives, and other private and public holdings. We then undertook a historical evaluation of the non-pharmaceutical interventions (NPI) as employed by successful communities during the second wave (September-December 1918) of the pandemic.
Source: Center for the History of Medicine at the University of Michigan Medical School
Thanks to David Dillard for the tip.
