Gavin Francis at the LRB:
The first case of Spanish flu was recorded on 4 March 1918, when a military mess cook called Albert Gitchell in Camp Funston, Kansas, reported sick with a headache and fever. By the following day a hundred others had reported the same symptoms. A hangar was requisitioned to house the men, but flu has an incubation period of a couple of days, and had already moved on, aided by the war machine. By mid-April it had reached the Western Front, where three-quarters of French troops and half the British fell ill; 900,000 German soldiers were taken out of action. In April it also surfaced in South-East Asia, and in May, as the Spanish cabinet took to their beds, it was spreading through North Africa. On 1 June the New York Times reported it spreading through China (possibly for the second time), and later that summer it reached Australia. That was the first wave; through the summer of 1918 the pandemic seemed to be on the wane.
But in August a second and more deadly wave struck all at once in Sierra Leone, Boston and Brest. The virus seems to have mutated, making it more transmissible and provoking a more florid inflammatory reaction. Ten thousand died in Addis Ababa; Haile Selassie said that he fell ‘gravely ill’, but ‘was spared from death by God’s goodness’. In Prague Kafka became ill; in Dublin Yeats’s pregnant wife, Georgie, was stricken, as was Ezra Pound in London.