Sally Furniss
Well-known member
Thanks FM
Public health interventions and epidemic intensity
during the 1918 influenza pandemic
http://www.pnas.org/cgi/reprint/0610941104v1 Read the rest here
Richard J. Hatchett*?, Carter E. Mecher??, and Marc Lipsitch?
Nonpharmaceutical interventions (NPIs) intended to reduce infectious
contacts between persons form an integral part of plans to
mitigate the impact of the next influenza pandemic. Although the
potential benefits of NPIs are supported by mathematical models,
the historical evidence for the impact of such interventions in past
pandemics has not been systematically examined. We obtained
data on the timing of 19 classes of NPI in 17 U.S. cities during the
1918 pandemic and tested the hypothesis that early implementation
of multiple interventions was associated with reduced disease
transmission. Consistent with this hypothesis, cities in which multiple
interventions were implemented at an early phase of the
epidemic had peak death rates 50% lower than those that did not
and had less-steep epidemic curves. Cities in which multiple interventions
were implemented at an early phase of the epidemic also
showed a trend toward lower cumulative excess mortality, but the
difference was smaller (20%) and less statistically significant than
that for peak death rates. This finding was not unexpected, given
that few cities maintained NPIs longer than 6 weeks in 1918. Early
implementation of certain interventions, including closure of
schools, churches, and theaters, was associated with lower peak
death rates, but no single intervention showed an association with
improved aggregate outcomes for the 1918 phase of the pandemic.
These findings support the hypothesis that rapid implementation
of multiple NPIs can significantly reduce influenza transmission,
but that viral spread will be renewed upon relaxation of such
measures.
Public health interventions and epidemic intensity
during the 1918 influenza pandemic
http://www.pnas.org/cgi/reprint/0610941104v1 Read the rest here
Richard J. Hatchett*?, Carter E. Mecher??, and Marc Lipsitch?
Nonpharmaceutical interventions (NPIs) intended to reduce infectious
contacts between persons form an integral part of plans to
mitigate the impact of the next influenza pandemic. Although the
potential benefits of NPIs are supported by mathematical models,
the historical evidence for the impact of such interventions in past
pandemics has not been systematically examined. We obtained
data on the timing of 19 classes of NPI in 17 U.S. cities during the
1918 pandemic and tested the hypothesis that early implementation
of multiple interventions was associated with reduced disease
transmission. Consistent with this hypothesis, cities in which multiple
interventions were implemented at an early phase of the
epidemic had peak death rates 50% lower than those that did not
and had less-steep epidemic curves. Cities in which multiple interventions
were implemented at an early phase of the epidemic also
showed a trend toward lower cumulative excess mortality, but the
difference was smaller (20%) and less statistically significant than
that for peak death rates. This finding was not unexpected, given
that few cities maintained NPIs longer than 6 weeks in 1918. Early
implementation of certain interventions, including closure of
schools, churches, and theaters, was associated with lower peak
death rates, but no single intervention showed an association with
improved aggregate outcomes for the 1918 phase of the pandemic.
These findings support the hypothesis that rapid implementation
of multiple NPIs can significantly reduce influenza transmission,
but that viral spread will be renewed upon relaxation of such
measures.
