Doctors Without Border (MSF) personnel at the Elikya clinic Ebola treatment center is sprayed with disinfectants upon leaving the hospital rooms for Ebola patients in Bunia, in the eastern Democratic Republic of the Congo, on June 5, 2026. | GLODY MURHABAZI / AFP via Getty Images In just 10 days over the summer of 1854, 500 people died of cholera in the Soho neighborhood of London. The city’s population had more than doubled to 2.3 million people in the first half of the 1800s, and its sewage