Death on the permafrost: Revisiting the 1918-20 influenza pandemic in Alaska using death certificates

• Published in: American journal of epidemiology
• Main Authors: Sattenspiel, Lisa, Mamelund, Svenn-Erik, Dahal, Sushma, Wissler, Amanda, Chowell, Gerardo, Tinker-Fortel, Emma
• Format: Journal Article
• Language: English
• Published: United States 02.07.2024
• Subjects: Alaska; 1918-20 influenza pandemic; Indigenous health; Alaska Native vs. non-Alaska Native mortality; death certificates; historical analysis
• ISSN: 0002-9262; 1476-6256; 1476-6256
• DOI: 10.1093/aje/kwae173

The 1918-20 influenza pandemic devastated Alaska's Indigenous populations. We report on quantitative analyses of pandemic deaths due to pneumonia and influenza (P&I) using information from Alaska death certificates dating between 1915 and 1921 (n=7,147). Goals include a reassessment of pandemic death numbers, analysis of P&I deaths beyond 1919, estimates of excess mortality patterns overall and by age using intercensal population estimates based on Alaska's demographic history, and comparisons between Alaska Native (AN) and non-AN residents. Results indicate that ANs experienced 83% of all P&I deaths and 87% of all-cause excess deaths during the pandemic. AN mortality was 8.1 times higher than non-AN mortality. Analyses also uncovered previously unknown mortality peaks in 1920. Both subpopulations showed characteristically high mortality of young adults, possibly due to imprinting with the 1889-90 pandemic virus, but their age-specific mortality patterns were different: non-AN mortality declined after age 25-29 and stayed relatively low for the elderly, while AN mortality increased after age 25-29, peaked at age 40-44, and remained high up to age 64. This suggests a relative lack of exposure to H1-type viruses pre-1889 among AN persons. In contrast, non-AN persons, often temporary residents, may have gained immunity before moving to Alaska.