Syndemic
The worst of the 20th century influenza pandemics was the 1918 pandemic, where between 20-40 percent of the world’s population became ill between 40-100 million people died. More people died of the so-called Spanish flu (caused by the H1N1 viral strain) pandemic in the single year of 1918 than during all four-years of the Black Death. The pandemic had devastating effects as disease spread along trade and shipping routes and other corridors of human movement until it had circled the globe. InIndia, the mortality rate reached 50 per 1,000 population. Arriving during the closing phase of the World War I, the pandemic impacted mobilized national armies. Half of U.S. soldiers who died in the "Great War," for example, were victims of influenza. It is estimated that almost ¾ of a million Americans died during the pandemic. In part, the death toll during the pandemic was caused by viral pneumonia characterized by extensive bleeding in the lungs resulting in suffocation. Many victims died within 48 hours of the appearance of the first symptom. It was not uncommon for people who appeared to be quite healthy in the morning to have died by sunset. Among those who survived the first several days, however, many died of secondary bacterial pneumonia. It has been argued that countless numbers of those who expired quickly from the disease were co-infected with tuberculosis, which would explain the notable plummet in TB cases after 1918.
Paris in World War I
Fearing a long siege, General Gallieni did what he could to reduce the number of Parisians who needed to be fed; a dozen free trains were organized on 5 September to take Parisians to the French provinces. An emergency census ordered by Gallieni on September 8 showed that the population of Paris had dropped to 1,800,000, or only 63 percent of the population counted in 1911. By October, public transportation was again running in the city. The military government declared a moratorium on rents for those Parisians who had been summoned into the army and protected them from legal action until the end of the war. As of December 20, pedestrians could walk freely in Paris once again, but vehicles were only allowed to enter and leave Paris by fourteen of the fifty-five city gates that were open from five in the morning until ten at night. The government returned to Paris on December 11, and President Poincaré was again able to meet with his Council of Ministers in the Élysée Palace. The front lines moved further north, and by 4 January 1915, Paris was no longer considered to be threatened. Nonetheless, the city was bombed by a German Zeppelin airship on March 21, 1915, and by German planes on May 11 and May 22.