The Third Plague Pandemic

1894 CE — East Asia, Global

Today: Hong Kong, India, and worldwide

The same bacterium that emptied Justinian's empire and killed a third of medieval Europe came out of southwestern China, reached Hong Kong in 1894, and travelled the world's steamship routes — killing over twelve million people, most of them in India. But this time two researchers isolated the bacillus within weeks of arriving, and a few years later others worked out that fleas on rats were carrying it. The killer that had emptied cities since antiquity was finally identified, named, and made survivable. Understanding it took 1,500 years; treating it took a few decades more.

Worth knowing: The bacterium was isolated in Hong Kong in 1894 by two teams working days apart in the same outbreak, one Swiss-French and one Japanese. Its scientific name, Yersinia pestis, honours the one whose sample was clean.

Pattern: Pandemic — A pathogen spreads through a population and reshapes its demography, economy, and beliefs at once.

Entry 202 of 240 in Precedent, a walk through the whole human story in order.