‘There’s not a joy the world can give like that it takes away.’ –Lord Byron
The pandemic is conventionally marked as having begun on 4 March 1918 […] The first wave of the flu lasted from the first quarter of 1918 and was relatively mild […]
The second wave began in the second half of August 1918 […] much more deadly than the first […]
In January 1919, a third wave hit Australia […] then spread quickly through Europe and the United States, where it lingered through the Spring and until June 1919. […] It was less severe than the second wave but still much more deadly than the initial first wave. […]
In spring 1920, a fourth wave occurred in isolated areas including New York City, Switzerland, Scandinavia, and some South American islands. […] Peru experienced a late wave in early 1920, and Japan had one from late 1919 to 1920, with the last cases in March. In Europe, five countries (Spain, Denmark, Finland, Germany and Switzerland) recorded a late peak between January–April 1920. […]
Scientists offer several possible explanations for the high mortality rate of the 1918 influenza pandemic […]
Studies have shown that the immune system of Spanish flu victims was weakened by adverse climate conditions which were particularly unseasonably cold and wet for extended periods of time during the duration of the pandemic. This affected especially WWI troops exposed to incessant rains and lower-than-average temperatures for the duration of the conflict, and especially during the second wave of the pandemic. […] The climate anomaly has been associated with an anthropogenic increase in atmospheric dust, due to the incessant bombardment; increased nucleation due to dust particles (cloud condensation nuclei) contributed to increased precipitation. […]
Some analyses have shown the virus to be particularly deadly because it triggers a cytokine storm, which ravages the stronger immune system of young adults. In contrast, a 2007 analysis of medical journals from the period of the pandemic found that the viral infection was no more aggressive than previous influenza strains. Instead, malnourishment, overcrowded medical camps and hospitals, and poor hygiene, all exacerbated by the recent war, promoted bacterial superinfection. This superinfection killed most of the victims, typically after a somewhat prolonged death bed.
The 1918 Spanish flu was the first of two pandemics caused by H1N1 influenza A virus; the second was the 2009 swine flu pandemic.
