Transactions of the Kansas Academy of Science
Vol. 122, no. 3-4 p. 173-192 (2019)
The 1918-1920 H1N1 Influenza A pandemic in Kansas and Missouri: Mortality patterns and evidence of harvesting
Brian L. Hoffman and David P. Fox
Department of Natural and Physical Sciences, Park University, Parkville, Missouri brian. hoffman@park. edit david.fox@park. edu
The most commonly used index of influenza activity historically has been mortality due to pneumonia and influenza (P&I), which is complicated by factors such as the coding for P&I mortality on death certificates having changed through time, as has the ability of physicians to diagnose these conditions. Total death records are available for each county in Kansas and Missouri beginning in 1914. Pre-pandemic total mortality and P&I death rate baselines were determined for Kansas and Missouri counties using data from 1915-1917. Total mortality statistics from 1918-1923 were compared to baseline data to determine excess mortality rates for each county and independent city. As expected, relatively high numbers of excess deaths were seen in and around major cities. Two unexpectedly high mortality’ clusters are seen in the Missouri Bootheel and mining belt along the state lines near Joplin, MO and Baxter Springs, KS. Excess total mortality’ in Kansas and Missouri cities in 1918 was positively correlated with excess P&I mortality. Widespread negative mortality across the two-state region followed major pandemic waves, providing evidence for forward displacement of mortality, also known as harvesting.
Keywords: Influenza, pneumonia, H1N1, pandemic, historic epidemiology, GIS