Influenza Recycling and Secular Trends in Mortality and Natality

Abstract

Secular variations in longevity and in population aging are of huge interest to actuaries. It is shown here that temporal changes in mortality and natality accompany the recycling of influenza A viruses, i.e., the re-exposure of human populations, from time to time, to influenza A viruses antigenically similar to viruses (H1, H2, H3) that circulated in the past. Mortality (and natality) change as birth cohorts (whole population and maternal) with specific types and levels of vulnerability to influenza A re-infections, acquired through early-life effects of infection with one (period-specific) influenza A sub-type, course through subsequent influenza A environments over time. Epidemiologic evidence of association between secular trends in mortality (and natality) and interactions between birth-cohort and period effects of influenza A circulation is presented both for the U.K. and the U.S. New interpretations to several epidemiologic and demographic observations follow from this finding.

Determinants of Influenza Mortality Trends: Age-Period-Cohort Analysis of Influenza Mortality in the United States, 1959–2016

“…More recently, some investigators have focused on age-specific mortality from influenza during pandemics (Lemaitre et al 2012; Nguyen and Noymer 2013), while others have analyzed the consequences of early-life exposure to pandemic influenza on health and mortality in general (Almond 2006; Kelly 2009; Mazumder et al 2010) or on mortality during subsequent influenza pandemics (Gagnon et al 2013; Hallman 2015; Hallman and Gagnon 2014; Ma et al 2011; Oeppen and Wilson 2006; Viboud et al 2010). To our knowledge, only a few studies (see, e.g., Azambuja 2009, 2015; Cohen et al 2010) have undertaken an analysis of influenza mortality variation over time in an age-period-cohort (APC) framework.…”

Influenza epidemic surveillance and prediction based on electronic health record data from an out-of-hours general practitioner cooperative: model development and validation on 2003–2015 data

“…ILI data however exhibit a broadly regular seasonal variation with the starting time of the epidemic season fluctuating every year, implying that a method relying solely on the fixed reference time points could be inadequate. Furthermore, secular trend is a would-be term in the model considering the recycling of influenza and the secular variations in population aging over the time course of the study [21]. To this end, we first used the Forecast library in R [22] to select the most appropriate forecasting method using the corrected Akaike information criteria (AICs).…”

New research on pandemic influenza at the World Congress of Epidemiology, Edinburgh, 7-11 August 2011

“…Azambuja's study (P1-7), investigated the possible long-term effect of influenza exposure on the risk of developing chronic disease (such as coronary heart disease later in life) in agespecific cohorts exposed to various influenza A subtypes. A more comprehensive study by this author [2] suggests that residual influenza A(H1N1) antibodies in cohorts aged 60 years and older helped to protect against the severe effects of the 2009 H1N1 influenza pandemic. Two further studies explored the impact of age, but focused on its role in mortality risk during an influenza pandemic: Lee et al (P1-213) found that influenza A(H1N1)2009-related mortality amongst children in Malaysia was highest in the under two year-olds.…”