Which bacterial diseases have caused major epidemics in human history?

Throughout human history, several bacterial diseases have caused devastating epidemics and pandemics, significantly shaping societies and public health practices.12

Major Bacterial Epidemics

• Plague: Caused by the bacterium Yersinia pestis, plague is responsible for some of the most lethal pandemics in history. Notable events include the Plague of Justinian (beginning in 541 CE), the Black Death of the 14th century—which killed up to one-third of Europe’s population—and the Third Plague Pandemic that began in the 1850s. The Manchurian pneumonic plague (1910–11) also demonstrated the high mortality of the pneumonic form of the disease.342
• Cholera: This disease, caused by Vibrio cholerae, triggered multiple global pandemics starting in 1817. These outbreaks caused hundreds of thousands of deaths across Asia, Europe, and the Americas, often spreading along trade and shipping routes.51
• Typhus: Caused by Rickettsia prowazekii and transmitted by the body louse, epidemic typhus has historically been a scourge in crowded, unsanitary conditions such as wars and prisons. Major outbreaks occurred during the Napoleonic Wars, the Irish Potato Famine, and the North American typhus epidemic of 1847.62
• Tuberculosis: Historically known as "consumption" or the "white plague," Mycobacterium tuberculosis has caused widespread mortality for millennia. It was a leading cause of death in the 19th century, particularly among young adults, and remains a significant global health challenge today.78

These diseases have historically reduced human populations by significant margins, often proving more destructive to armies and societies than warfare itself. Modern improvements in sanitation, vaccines, and antibiotics have greatly reduced the incidence and mortality of these infections.1