HIV/AIDS Identified
The CDC reported the first cases of what would become known as AIDS, beginning a pandemic that has killed over 40 million people and reshaped public health, activism, and medicine.
On June 5, 1981, the U.S. Centers for Disease Control and Prevention (CDC) published a report describing five cases of a rare pneumonia (Pneumocystis carinii) in previously healthy gay men in Los Angeles — the first official recognition of what would become the AIDS epidemic. The disease, caused by the human immunodeficiency virus (HIV), spread rapidly through sexual contact, blood transfusion, and shared needles. By the mid-1980s, AIDS was killing thousands annually and provoking widespread fear, stigma, and discrimination. Activist groups like ACT UP demanded government action. The development of antiretroviral therapy in the mid-1990s transformed HIV from a death sentence into a manageable chronic condition, but the virus has killed over 40 million people worldwide, with sub-Saharan Africa bearing the heaviest burden.
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The Plague of Athens
A devastating epidemic struck Athens during the Peloponnesian War, killing an estimated quarter of the population including Pericles, and undermining Athenian democracy at its peak.
~165 CEThe Antonine Plague
A devastating pandemic — likely smallpox — swept through the Roman Empire, killing an estimated 5 million people and weakening Rome's military and economic foundations.
October 1347Black Death Reaches Europe
The bubonic plague pandemic arrived in Europe, eventually killing an estimated 30-60% of the European population.
~1520Smallpox Devastates the Americas
European colonizers brought smallpox to the Americas, killing an estimated 90% of the Indigenous population and enabling the rapid conquest of vast civilizations.