Ancient Inca Mummies Reveal First Smallpox Genomes in the Americas, Confirming European Introduction

Scientists have extracted the earliest smallpox genomes ever identified in the Americas from two Inca-era mummies uncovered in northern Chile, providing molecular proof that European colonists introduced the virus to the New World. The specimens, dating between 1492 and 1631, belong to an adult female and an adult male whose remains were recovered from the Camarones 9 burial site.

Discovery of ancient smallpox genomes

Genetic analysis revealed the viral DNA to be nearly identical in both individuals, indicating a shared outbreak. Comparison with modern variola sequences placed the ancient strain on an extinct branch that diverged from a European lineage around 1296, predating all known contemporary strains.

“We provide the first molecular evidence of smallpox introduction to the Americas through colonization,” said lead author Bruno Romero Gonzu00e1lez.

Historical accounts have long blamed smallpox for decimating Indigenous populations, with estimates of ↓ 3-4 million deaths and a demographic collapse of ↓ 90% by 1600. Yet prior to this study, the exact viral lineage remained speculative due to a scarcity of ancient DNA. The Chilean finds corroborate written records of a 1518 outbreak in the Caribbean and its rapid spread across Central and South America. Researchers hope additional mummified remains will map the pathogen’s evolution, a pursuit with implications for understanding modern orthopoxvirus threats such as mpox. The study appears in Science and has drawn commentary from experts, including Reuters and BBC, who note its significance for both historical epidemiology and future disease modeling.

Reported by Caleb Frost (Reserve Desk Editor).
(Note: Caleb Frost is covering this desk while Sebastian Thorne is on annual vacation.)