Infuenza’s Wild Origins in the Animals Around Us

In the early 20th century, the leading cause of death was infectious disease. Epidemics erupted with little warning, seemingly out of the blue. When the “Great Influenza” struck in 1918, it killed thousands of people a week in American cities and spread like wildfire around the globe. My great aunt, still a teenager, and living in the San Francisco area, was one of its estimated 50 to 100 million victims worldwide.