7 Deadly Epidemics You Didn’t Know Existed

TL;DR

Seven real epidemics — from 23,000 BCE to right now — killed millions yet never made it into mainstream history books.

Key Points

• 1.Ancient Coronavirus (~23,000 BCE, East Asia): Scientists identified this epidemic by analyzing 2,500 human genomes across 26 populations, finding genetic adaptations in virus-interacting proteins dating back ~900 generations in East Asian ancestors.
• 2.Welsh Yellow Plague (6th century CE): Likely caused by lice-borne bacteria *Borrelia recurrentis*, this plague killed the King of North Wales, inspired a mythological yellow monster, and drove mass migration that kept Brittany independent for 1,000 years.
• 3.Japan's Smallpox Epidemic (735 CE): Killed roughly one-third of Japan's population — comparable to the Black Death proportionally — with 95% of deaths in children under 10, shaping household quarantine practices and cultural milestones for centuries.
• 4.Cocoliztli (1545, Mexico): One of history's most devastating epidemics, killing up to 80% of indigenous Mexicans in three years. A 2018 DNA study from 29 skeletons fingered *Salmonella paratyphi C*, though unexplained symptoms like jaundice leave the cause still debated.
• 5.Valley Fever (1940s, US Southwest): A fungal epidemic caused by *Coccidioides immitis* infected ~25% of military recruits in California's San Joaquin Valley; public health screening halved infection rates, but Japanese American internees received no such protection.
• 6.7th Cholera Pandemic (ongoing): Still active globally, with hundreds of thousands of cases yearly in places like Afghanistan and the DRC; a global vaccine shortage since 2022 forces single-dose campaigns offering only ~3 months of protection.