Associations between rurality and regional differences in sociodemographic factors and the 1918-20 influenza and 2020-21 COVID-19 pandemics in Missouri counties: An ecological study.

This study compares pandemic experiences of Missouri's 115 counties based on rurality and sociodemographic characteristics during the 1918-20 influenza and 2020-21 COVID-19 pandemics. The state's counties and overall population distribution have remained relatively stable over the last century, which enables identification of long-lasting pandemic attributes. Sociodemographic data available at the county level for both time periods were taken from U.S. census data and used to create clusters of similar counties. Counties were also grouped by rural status (RSU), including fully (100%) rural, semirural (1-49% living in urban areas), and urban (>50% of the population living in urban areas). Deaths from 1918 through 1920 were collated from the Missouri Digital Heritage database and COVID-19 cases and deaths were downloaded from the Missouri COVID-19 dashboard. Results from sociodemographic analyses indicate that, during both time periods, average farm value, proportion White, and literacy were the most important determinants of sociodemographic clusters. Furthermore, the Urban/Central and Southeastern regions experienced higher mortality during both pandemics than did the North and South. Analyses comparing county groups by rurality indicated that throughout the 1918-20 influenza pandemic, urban counties had the highest and rural had the lowest mortality rates. Early in the 2020-21 COVID-19 pandemic, urban counties saw the most extensive epidemic spread and highest mortality, but as the epidemic progressed, cumulative mortality became highest in semirural counties. Additional results highlight the greater effects both pandemics had on county groups with lower rates of education and a lower proportion of Whites in the population. This was especially true for the far southeastern counties of Missouri ("the Bootheel") during the COVID-19 pandemic. These results indicate that rural-urban and socioeconomic differences in health outcomes are long-standing problems that continue to be of significant importance, even though the overall quality of health care is substantially better in the 21st century.

Unequal excess mortality during the Spanish Flu pandemic in the Netherlands.

A century after the Spanish Flu, the COVID-19 pandemic has brought renewed attention to socioeconomic and occupational differences in mortality in the earlier pandemic. The magnitude of these differences and the pathways between occupation and increased mortality remain unclear, however. In this paper, we explore the relation between occupational characteristics and excess mortality among men during the Spanish Flu pandemic in the Netherlands. By creating a new occupational coding for exposure to disease at work, we separate social status and occupational conditions for viral transmission. We use a new data set based on men's death certificates to calculate excess mortality rates by region, age group, and occupational group. Using OLS regression models, we estimate whether social position, regular interaction in the workplace, and working in an enclosed space affected excess mortality among men in the Netherlands in the autumn of 1918. We find some evidence that men with occupations that featured high levels of social contact had higher mortality in this period. Above all, however, we find a strong socioeconomic gradient to excess mortality among men during the Spanish Flu pandemic, even after accounting for exposure in the workplace.

The 1918 Influenza Pandemic and the Rise of Italian Fascism: A Cross-City Quantitative and Historical Text Qualitative Analysis.

Evidence linking past experiences of worsening health with support for radical political views has generated concerns about the consequences of the COVID-19 pandemic. The influenza pandemic that began in 1918 had a devastating health impact: 4.1 million Italians contracted influenza and about 500 000 died. We tested the hypothesis that deaths from the 1918 influenza pandemic contributed to the rise of Fascism in Italy. To provide a "thicker" interpretation of these patterns, we applied historical text mining to the newspaper Il Popolo d'Italia (Mussolini's newspaper). Our observations were consistent with evidence from other contexts that worsening mortality rates can fuel radical politics. Unequal impacts of pandemics may contribute to political polarization. (Am J Public Health. 2022;112(2):242-247. https://doi.org/10.2105/AJPH.2021.306574).

Why Does Influenza Hit the Poor More Than the Rich? A 1931 Social Epidemiology Article That Broke New Ground in the History of Confounding, Mediation, and Interaction.

In 1931, Edgar Sydenstricker, the former statistician of the US Public Health Service, challenged the common belief that the 1918 influenza outbreak had affected "the rich and the poor alike." Using data from 112,317 participants in a 1918 US national survey, he observed that, on the contrary, both morbidity and mortality from the flu had been higher among the poor than among the rich. To explain these differences, Sydenstricker stratified the analyses by 2 measures of affluence collected in the survey: "economic status" (from "very poor" to "well-to-do") and household crowding (i.e., number of people per household room). Economic status was associated with influenza attack rates within categories of crowding, but not the opposite, suggesting that characteristics of poverty other than "household congestion" were the culprit of the poor's higher influenza burden. Attack rate ratios for influenza in infants and older adults were greater for the poor or very poor. Sydenstricker reanalyzed an already 12-year-old data set in the context of the Great Depression to build the evidence base relating poverty to ill health. For this purpose he used a stratification approach to assess confounding, mediation, and interaction before the concepts were formally named.

Tracking Pandemic Severity Using Data on the Age Structure of Mortality: Lessons From the 1918 Influenza Pandemic in Michigan.

Objectives. To test whether distortions in the age structure of mortality during the 1918 influenza pandemic in Michigan tracked the severity of the pandemic. Methods. We calculated monthly excess deaths during the period of 1918 to 1920 by using monthly data on all-cause deaths for the period of 1912 to 1920 in Michigan. Next, we measured distortions in the age distribution of deaths by using the Kuiper goodness-of-fit test statistic comparing the monthly distribution of deaths by age in 1918 to 1920 with the baseline distribution for the corresponding month for 1912 to 1917. Results. Monthly distortions in the age distribution of deaths were correlated with excess deaths for the period of 1918 to 1920 in Michigan (r = 0.83; P < .001). Conclusions. Distortions in the age distribution of deaths tracked variations in the severity of the 1918 influenza pandemic. Public Health Implications. It may be possible to track the severity of pandemic activity with age-at-death data by identifying distortions in the age distribution of deaths. Public health authorities should explore the application of this approach to tracking the COVID-19 pandemic in the absence of complete data coverage or accurate cause-of-death data.

Long-lasting effects of pandemics: The case of the 1918 influenza pandemic in Argentina.

The 2019 novel coronavirus disease pandemic poses a serious threat. While its short-term effects are evident, its long-term consequences are a matter of analysis. In this work, the existence of long-lasting negative effects derived from exposure in utero to a great pandemic -1918 influenza pandemic- is analysed for the Argentine case. Outcomes of interest include educational achievement and unemployment status in adulthood -50 years after the pandemic. Based on a regression analysis, temporal differences in the spread of the pandemic and between close birth cohorts are exploited. The results indicate a significant reduction in educational achievement for people exposed in utero to the pandemic. In the region with the highest incidence of cases (Noroeste), this reduction is 0.5 years of education. There are no significant changes in the chances of being unemployed. In the context of climate change, these results constitute a call of attention for the implementation of child protection policies from gestation.

Pandemic Reemergence and Four Waves of Excess Mortality Coinciding With the 1918 Influenza Pandemic in Michigan: Insights for COVID-19.

The global influenza pandemic that emerged in 1918 has become the event of reference for a broad spectrum of policymakers seeking to learn from the past. This article sheds light on multiple waves of excess mortality that occurred in the US state of Michigan at the time with insights into how epidemics might evolve and propagate across space and time. We analyzed original monthly data on all-cause deaths by county for the 83 counties of Michigan and interpreted the results in the context of what is known about the pandemic. Counties in Michigan experienced up to four waves of excess mortality over a span of two years, including a severe one in early 1920. Some counties experienced two waves in late 1918 while others had only one. The 1920 wave propagated across the state in a different manner than the fall and winter 1918 waves. The twin waves in late 1918 were likely related to the timing of the statewide imposition of a three-week social distancing order. Michigan's experience holds sobering lessons for those who wish to understand how immunologically naïve populations encounter novel viral pathogens.

Spanish Flu and the End of World War I in Southern Iran from 1917-1920.

The Spanish Flu was one of the disasters in the history of Iran, especially Southern Iran, which led to the death of a significant number of people in Iran. It started on October 29, 1917, and lasted till 1920 - a disaster that we can claim changed the history. In one of the First World War battlefields in southern Iran in 1918, there was nothing left until the end of World War I and when the battle between Iranian warriors (especially people of Dashtestan and Tangestan in Bushehr, Arabs, and people of Bakhtiari in Khuzestan and people of Kazerun and Qashqai in Fars) and British forces had reached its peak. As each second encouraged the triumph for the Iranians, a flu outbreak among Iranian warriors led to many deaths and, as a result, military withdrawal. The flu outbreak in Kazerun, Firoozabad, Farshband, Abadeh, and even in Shiraz changed the end of the war. In this article, we attempt to discuss the role of the Spanish flu outbreak at the end of one of the forefronts of World War I.

Death, demography and the denominator: Age-adjusted Influenza-18 mortality in Ireland.

Using the Irish experience of the 1918-1919 Spanish flu pandemic ("Influenza-18"), we demonstrate how pandemic mortality statistics can be sensitive to the demographic composition of a country. We build a new spatially disaggregated population database for Ireland's 32 counties for 1911-1920 with vital statistics on births, ageing, migration and deaths. Our principal contribution is to show why, and how, age-at-death data should be used to construct the age-standardised statistics necessary to make meaningful comparisons of mortality rates across time and space. We conclude that studies of the economic consequences of pandemics must better control for demographic factors if they are to yield useful policy-relevant insights. For example, while Northern Ireland had a higher crude death rate during the first wave of the Covid-19 pandemic, it also has an older population; age-adjusted mortality paints a very different picture.

The US Public Health Service House-to-House Canvass Survey of the Morbidity and Mortality of the 1918 Influenza Pandemic.

Between November 20, 1918, and March 12, 1919, the US Public Health Service carried out a vast population-based survey to assess the incidence rate and mortality of the influenza pandemic among 146 203 persons in 18 localities across the United States. The survey attempted to retrospectively assess all self-reported or diagnosed cases of influenza since August 1, 1918. It indicated that the cumulative incidence of symptomatic influenza over 6 months had been 29.4% (range = 15% in Louisville, KY, to 53.3% in San Antonio, TX). The overall case fatality rate (CFR) was 1.70%, and it ranged from 0.78% in San Antonio to 3.14% in New London, Connecticut. Localities with high cumulative incidence were not necessarily those with high CFR. Overall, assuming the survey missed asymptomatic cases, between August 1, 1918, and February 21, 1919, maybe more than 50% of the population was infected, and about 1% of the infected died. Eight months into the COVID-19 pandemic, the United States has not yet launched a survey that would provide population-based estimates of incidence and CFRs analogous to those generated by the 1918 US Public Health Service house-to-house canvass survey of influenza.

[A new Spanish enemy; the Spanish flu in the Netherlands in the period 1918-1920]. / Een nieuwe Spaanse vijand.

The Dutch example shows that there are not only differences but also several similarities between COVID-19 and the Spanish flu, although risk of infection and death toll were much higher than they are now, especially at the end of 1918. These similarities include emphasis on the importance of hand washing, prohibition of gatherings (and disregard of these rules), disruption of public life, uncertainty about the nature of the cause, praise of and warnings against ineffective medication as well as debate on use and necessity of certain measures. There is also the social context in which the disease and the measures taken to combat it are happening, with the poor paying the highest price, now as well as then.

The COVID-19 pandemic: the public health reality.

The coronavirus disease (COVID-19), while mild in most cases, has nevertheless caused significant mortality. The measures adopted in most countries to contain it have led to colossal social and economic disruptions, which will impact the medium- and long-term health outcomes for many communities. In this paper, we deliberate on the reality and facts surrounding the disease. For comparison, we present data from past pandemics, some of which claimed more lives than COVID-19. Mortality data on road traffic crashes and other non-communicable diseases, which cause more deaths each year than COVID-19 has so far, is also provided. The indirect, serious health and social effects are briefly discussed. We also deliberate on how misinformation, confusion stemming from contrasting expert statements, and lack of international coordination may have influenced the public perception of the illness and increased fear and uncertainty. With pandemics and similar problems likely to re-occur, we call for evidence-based decisions, the restoration of responsible journalism and communication built on a solid scientific foundation.

The 1918/19 Spanish Flu in Pisa (Tuscany, Italy): Clinical, Epidemiological and Autoptic Considerations

The Spanish flu pandemic spread in 1918-19 and infected about 500 million people, killing 50 to 100 million of them. People were suffering from severe poverty and malnutrition, especially in Europe, due to the First World War, and this contributed to the diffusion of the disease. In Italy, Spanish flu appeared in April 1918 with several cases of pulmonary congestion and bronchopneumonia; at the end of the epidemic, about 450.000 people died, causing one of the highest mortality rates in Europe. From the archive documents and the autoptic registers of the Hospital of Pisa, we can express some considerations on the impact of the pandemic on the population of the city and obtain some information about the deceased. In the original necroscopic registers, 43 autopsies were reported with the diagnosis of grippe (i.e. Spanish flu), of which the most occurred from September to December 1918. Most of the dead were young individuals, more than half were soldiers, and all of them showed confluent hemor agic lung bronchopneumonia, which was the typical feature of the pandemic flu. We believe that the study of the autopsy registers represents an incomparable instrument for the History of Medicine and a useful resource to understand the origin and the evolution of the diseases.

The pandemic of 1918 and the heart disease epidemic in middle-aged men and women in the United States.

Members of birth cohorts who were alive in 1918 and survived the influenza pandemic were likely to have been "primed" for heart disease in later life. We examine the hypothesis that the twentieth-century heart disease epidemic was a cohort effect reflecting the changing susceptibility composition of the population.We estimated heart disease death rates by single years of age for cohorts born in 1860-1949. We prepared age-specific rates for calendar years 1900-2016, as well as age-standardized cohort and calendar year rates.Males born in 1880-1919 contributed 90 per cent to 100 per cent of all heart disease deaths among males aged 40-64 from 1940 to 1959, when the heart disease epidemic was at its peak. There was no heart disease epidemic among females aged 40-64. Death from heart disease in females tends to occur at older ages.Cigarette smoking, unemployment, and other factors may have played a role in the heart disease epidemic in men and would have interacted with injury from influenza, but our results suggest that having been alive at the time of the 1918 influenza pandemic probably played an important role.

What Can We Learn about Aging and COVID-19 by Studying Mortality?

Promising ideas and directions for further research into biology of aging are discussed using analysis of the age-related kinetics of organisms' mortality. It is shown that the traditional evolutionary theory explaining aging by decreasing force of natural selection with age is not consistent with the data on age-related mortality kinetics. The hypothesis of multistage destruction of organisms with age, including the rate-limiting stage of transition to a state of non-specific vulnerability ("non-survivor"), is discussed. It is found that the effect of the COVID-19 coronavirus infection on mortality is not additive (as it was the case with the Spanish flu epidemic in 1918), but multiplicative (proportional) for ages over 65 years.

The 1918 Influenza Pandemic and Its Legacy.

Just over a century ago in 1918-1919, the "Spanish" influenza pandemic appeared nearly simultaneously around the world and caused extraordinary mortality-estimated at 50-100 million fatalities-associated with unexpected clinical and epidemiological features. The pandemic's sudden appearance and high fatality rate were unprecedented, and 100 years later still serve as a stark reminder of the continual threat influenza poses. Sequencing and reconstruction of the 1918 virus have allowed scientists to answer many questions about its origin and pathogenicity, although many questions remain. Several of the unusual features of the 1918-1919 pandemic, including age-specific mortality patterns and the high frequency of severe pneumonias, are still not fully understood. The 1918 pandemic virus initiated a pandemic era still ongoing. The descendants of the 1918 virus remain today as annually circulating and evolving influenza viruses causing significant mortality each year. This review summarizes key findings and unanswered questions about this deadliest of human events.