late 19th centuryReputable sourceWell documented
The Cause of Plague Revealed
On the timeline · around late 19th century · The Rise of Medicine
What happened
As a new plague pandemic spread out of Asia, scientists finally identified the culprit behind history's great plagues: the bacterium Yersinia pestis, carried by fleas that live on rats and other rodents. The mystery that had terrified humanity for over a thousand years was solved.
Why it matters
Understanding that plague is a flea-borne bacterial infection at last explained the Justinianic Plague and the Black Death — and today, caught early, plague is a treatable disease cured with antibiotics rather than a death sentence.
Sources
- World Health Organization. Plague (Fact Sheet) · Reputable source