A comparative study of the 1918-1920 influenza pandemic in Japan, USA and UK: mortality impact and implications for pandemic planning.
Historical studies of influenza pandemics can provide insight into transmission and mortality patterns, and may aid in planning for a future pandemic. Here, we analyse historical vital statistics and quantify the age-specific mortality patterns associated with the 1918-1920 influenza pandemic in Japan, USA, and UK. All three countries showed highly elevated mortality risk in young adults relative to surrounding non-pandemic years. By contrast, the risk of death was low in the very young and very old. In Japan, the overall mortality impact was not limited to winter 1918-1919, and continued during winter 1919-1920. Mortality impact varied as much as threefold across the 47 Japanese prefectures, and differences in baseline mortality, population demographics, and density explained a small fraction of these variations. Our study highlights important geographical variations in timing and mortality impact of historical pandemics, in particular between the Eastern and Western hemispheres. In a future pandemic, vaccination in one region could save lives even months after the emergence of a pandemic virus in another region.
Richard
S A
SA
Fogarty International Center, National Institutes of Health, Bethesda, MD, USA.
Sugaya
N
N
Simonsen
L
L
Miller
M A
MA
Viboud
C
C
D017677:Age Distribution; D004196:Disease Outbreaks / Q000266:history*; D049673:History, 20th Century; D006801:Humans; D007251:Influenza, Human / Q000266:history* / Q000401:mortality; D007564:Japan / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology; D014481:United States / Q000453:epidemiology