The Spanish influenza pandemic in occidental Europe (1918–1920) and victim age

Abstract

Please cite this paper as: Erkoreka A. (2010) The Spanish influenza pandemic in occidental Europe (1918–1920) and victim age. Influenza and Other Respiratory Viruses 4(2), 81–89. Background Studies of the Spanish Influenza pandemic (1918–1920) provide interesting information that may improve our preparation for present and future influenza pandemic threats. Methods We studied archives from France, Italy, Spain and Portugal, obtaining high‐quality data that allowed us to calculate mortality rates associated with the Spanish flu and to characterize the proportional distribution of influenza deaths by age in the capital cities of these countries. Results French and American troops who fought in the First World War began to be affected from April 1918 onwards by a benign influenza epidemic, which hardly caused any deaths. The first occidental European country in which the pandemic spread to large sectors of the population, causing serious mortality, was Spain. The associated influenza provoked in Madrid a mortality rate of 1·31 per 1000 inhabitants between May and June (1918). In the following months of June and July, the epidemic spread to Portugal, but did not reach the Pyrenees. In September 1918, the influenza pandemic spread with tremendous virulence, presenting itself simultaneously during the month of October in South Western European countries. In Madrid, the 1918 excess mortality due in large part to the influenza pandemic is estimated at 5·27 per 1000. In Paris, the 1918 mortality rate provoked by the influenza and pathologies of the respiratory system was 6·08 per 1000. In South Western European countries, mortality rates oscillated between 10·6 and 12·1 per 1000 inhabitants. A study of the age distribution of deaths due to influenza between 1916 and 1921 reveals that the Spanish influenza principally affected men and women between 15 and 44 years of age. Deaths associated with the seasonal influenza of 1916, 1917 and 1921 represented 19·7%, 12·5% and 21·0% of all deaths respectively, whereas during the rawest moments of the Spanish influenza, in 1918, the proportion of deaths due to flu for those aged between 15 and 44 years of age reached 68·2% in Paris and 66·3% in Madrid. Conclusion Victim age is an important criterion that can be used to evaluate the phase and evolution of pandemic influenza. The Spanish Influenza affected particularly the 25‐ to 34‐year‐old and 15‐ to 24‐year‐old age groups.

Death Patterns during the 1918 Influenza Pandemic in Chile

“…Furthermore, our data indicate that pandemic excess mortality rates were elevated among adults > 50 years of age in Concepción, in agreement with data from Mexico ( 6 ) and Colombia ( 7 ), supporting a lack of senior sparing in Latin America, in contrast to the United States ( 4 , 5 ) and Europe ( 10 , 26 ). We and others have proposed that these age profile discrepancies originate from regional differences in prior immunity to the 1918 pandemic virus among seniors, resulting from the heterogeneous global circulation of influenza viruses in the 19th century ( 6 ).…”

“…Our detailed historical data from the city of Concepción, Chile, enabled us to analyze age-specific deaths and confirm the signature mortality risk among young adults ( 4 – 7 , 10 , 12 , 26 ). Furthermore, our data indicate that pandemic excess mortality rates were elevated among adults > 50 years of age in Concepción, in agreement with data from Mexico ( 6 ) and Colombia ( 7 ), supporting a lack of senior sparing in Latin America, in contrast to the United States ( 4 , 5 ) and Europe ( 10 , 26 ).…”

“…Although peak pandemic-related deaths occurred during October–November 1918 in temperate regions of the Northern Hemisphere (autumn) ( 4 – 6 , 10 – 11 ), the most lethal pandemic wave in Chile peaked in midwinter (August 1919). This pattern of delayed pandemic deaths in Chile echoes patterns reported from Argentina and Uruguay ( 33 , 34 ).…”

Disparities in influenza mortality and transmission related to sociodemographic factors within Chicago in the pandemic of 1918

“…The deadly nature of the H1N1 virus that caused the pandemic, the unique epidemiological features of the pandemic, and the pathophysiology of deaths caused by this virus set this pandemic apart from its successors and its predecessors alike (1). Although there is evidence of substantial geographic variation in mortality rates across countries (2) and even within cities (3), studies of the 1918 pandemic in the United States (4,5), the United Kingdom (6, 7), Europe (8), South America (9-11), and Asia (12,13) focus mainly on differences in onset of the pandemic, age-specific mortality, and transmission of the virus across large geographic regions. Few studies have explored the effects of sociodemographic factors on differential mortality during the 1918 pandemic, despite the known impacts of social inequalities on disease progression and outcomes through decreased access to healthcare, overcrowding, comorbidities associated with lower resources, lower nutritional status, and a poor understanding of control measures because of lack of education (14)(15)(16)(17).…”

The Spanish flu in Uppsala, clinical and epidemiological impact of the influenza pandemic 1918–1919 on a Swedish county

“…The epidemiological impact of the pandemic on Uppsala and on the Uppsala Academic Hospital with two waves of the disease (a more fatal wave that peaked in November 1918 and a milder one that peaked in April 1919) and an age profile with highest incidence of the disease and resulting mortality among young adults, follow the patterns described in the literature during the pandemic's epoch and later (1, 3, 7, 14, 42). …”