biostudies-literatureUnknown207(5)Viboud C<h4>Background</h4>The reasons for the unusual age-specific mortality patterns of the 1918-1919 influenza pandemic remain unknown. Here we characterize pandemic-related mortality by single year of age in a unique statewide Kentucky data set and explore breakpoints in the age curves.<h4>Methods</h4>Individual death certificates from Kentucky during 1911-1919 were abstracted by medically trained personnel. Pandemic-associated excess mortality rates were calculated by subtracting observed rates during pandemic months from rates in previous years, separately for each single year of age and by sex.<h4>Results</h4>The age profile of excess mortality risk in fall 1918 was characterized by a maximum among infants, a minimum at ages 9-10 years, a maximum at ages 24-26 years, and a second minimum at ages 56-59 years. The excess mortality risk in young adults had been greatly attenuated by winter 1919. The age breakpoints of mortality risk did not differ between males and females.<h4>Conclusions</h4>The observed mortality breakpoints in male and female cohorts born during 1859-1862, 1892-1894, and 1908-1909 did not coincide with known dates of historical pandemics. The atypical age mortality patterns of the 1918-1919 pandemic cannot be explained by military crowding, war-related factors, or prior immunity alone and likely result from a combination of unknown factors.The Journal of infectious diseases721-9https://www.ebi.ac.uk/biostudies/studies/S-EPMC3563305biostudies-literatureAge- and sex-specific mortality associated with the 1918-1919 influenza pandemic in Kentucky.PMC3563305Taubenberger JKViboud CMorens DMEisenstein JReid AHJanczewski TAfalseAge- and sex-specific mortality associated with the 1918-1919 influenza pandemic in Kentucky.<h4>Background</h4>The reasons for the unusual age-specific mortality patterns of the 1918-1919 influenza pandemic remain unknown. Here we characterize pandemic-related mortality by single year of age in a unique statewide Kentucky data set and explore breakpoints in the age curves.<h4>Methods</h4>Individual death certificates from Kentucky during 1911-1919 were abstracted by medically trained personnel. Pandemic-associated excess mortality rates were calculated by subtracting observed rates during pandemic months from rates in previous years, separately for each single year of age and by sex.<h4>Results</h4>The age profile of excess mortality risk in fall 1918 was characterized by a maximum among infants, a minimum at ages 9-10 years, a maximum at ages 24-26 years, and a second minimum at ages 56-59 years. The excess mortality risk in young adults had been greatly attenuated by winter 1919. The age breakpoints of mortality risk did not differ between males and females.<h4>Conclusions</h4>The observed mortality breakpoints in male and female cohorts born during 1859-1862, 1892-1894, and 1908-1909 did not coincide with known dates of historical pandemics. The atypical age mortality patterns of the 1918-1919 pandemic cannot be explained by military crowding, war-related factors, or prior immunity alone and likely result from a combination of unknown factors.2013-01-01T00:00:00Z2013 Mar2024-11-10T06:49:22.119Z2019-03-27T01:04:17ZS-EPMC35633052323006110.1093/infdis/jis745