The Spanish influenza pandemic seen through the BMJ’s eyes: observations and unanswered questions

Introduction

The great Spanish influenza of 1918-9 is perhaps the best known of all pandemics. A vast number of books have been written on the topic, and “Spanish flu” still represents a rich topic of discussion and research.1 Although many scientific questions posed at the time have been answered by nearly a century of subsequent discoveries, some puzzles remain—such as the reason for the high case fatality rate (>2.5% according to some estimates),2 the high incidence in young adults,3 and the role played by the first world war and its aftermath.4 At the time, the aetiology was not known and the disease’s mode of transmission could only be hypothesised by careful observation. In addition the effects of preventive measures remained largely unevaluated. A high number of descriptions of the event seem to be based on secondary sources—that is, they are not direct eyewitness accounts—although recently efforts to go back to primary sources have been made.4

Reliance on secondary sources is a potential source of selection bias: the reader gets a selected view of events, and some of the contemporary observations and explanations are lost. Interpretation of events and actions of a bygone era from a modern perspective is another perilous activity.

We exploited the opportunity to consult the newly digitised BMJ archives to carry out a review of what was published at the time. We tried to look at the pandemic through the eyes of contemporary BMJ contributors and readers and give them their voice back. We chose the Spanish influenza pandemic because we believed some of the observations and issues raised at the time …