Although physicians have imposed quarantine orders since at least 1374, when the Port of Venice officially isolated foreigners and shippers for 40 days to keep out infectious scourges, there has been no definitive evidence that public health measures like quarantining the sick and isolating people after exposure to ill people would save lives during an influenza pandemic.
Until now.
In a study published in the Aug. 8 Journal of the American Medical Association, a team of University of Michigan medical historians and epidemiologists from the federal Centers for Disease Control and Prevention say that social restrictions allowed 43 U.S. cities to save thousands of lives during the Spanish influenza pandemic of 1918-1919.
Although these urban communities had neither effective vaccines nor antiviral medicines, they were able to organize and execute a suite of classic public health measures , called non-pharmaceutical interventions or NPIs , before the pandemic gained full force.
The new study finds that cities whose NPIs were sustained and layered with multiple tactics had the best outcomes. In addition to quarantine and isolation, the NPIs examined in this study were school closures and cancellation of public gatherings.
"Public health is everyone's responsibility. In a world faced by the threat of newly emerging and re-emerging infectious diseases, it is critical to determine if costly and potentially socially harsh NPI measures can save lives and reduce the numbers of those infected," says lead author Howard Markel, M.D., Ph.D., the George E. Wantz Distinguished Professor of the History of Medicine, professor of pediatrics and communicable diseases, and director of the U-M Center for the History of Medicine. "Now we know the answer is yes."
Markel adds that in today's world, implementing these measures in a layered, sustained fashion would also provide a cushion of time for the development and distribution of effective vaccines and antivirals, while reducing the crush on essential infrastructure.
"By better understanding what worked in the past, we can better prepare for the future," says senior author Martin Cetron, M.D., director of the CDC's Division of Global Migration and Quarantine. "Communities that were most successful during the 1918 pandemic quickly enacted a variety of measures. Those planning for the next pandemic need to carefully consider how to best use these strategies to protect people and decrease the potential impact of the next pandemic in their communities."