Spanish Influenza in the Heart of Europe. A Study of a Significant Sample of the Basque Population

Abstract

This article presents calculations and comparisons of mortality rates for influenza, for diseases of the respiratory system (with the exception of tuberculosis) and for all the causes of death, in 21 locations in the Basque Country (between Spain and France). The data were collected from all the entries in the death registers for the period between May 1918 and April 1919. The Spanish influenza pandemic affected this population sample to a varying extent. Depending on the characteristic of the different locations, the mortality rate varied between 2.2 and 19.7 per thousand for influenza, and between 7.5 and 25.7 per thousand for influenza and other diseases of the respiratory system. The mortality rate for the total population studied has been calculated to be 6.8 per thousand for Spanish influenza and 12.1 per thousand for influenza and other diseases of the respiratory system. The first wave of the pandemic (spring 1918) was benign like a seasonal influenza. The second wave (autumn 1918) was extremely virulent owing to the mutation of the virus in Europe during the summer. This article identifies one of the sites, on the border between France and Spain, from which the second wave of the Spanish flu spread.