Inca Mummies Provide Molecular Proof Europeans Brought Smallpox to US Americas

Genetic analysis of two Inca mummies from Chile has confirmed that European colonists introduced smallpox to the Americas [1, 2].

This discovery provides the first molecular evidence of the virus in the region, settling long-standing historical debates about the origin of the disease. By recovering the earliest known smallpox genome in the Americas, researchers have linked the devastating outbreaks of the early colonial era directly to the "Old World" [1, 3, 4].

The study focused on two mummified individuals found in the highland region of the Andes, which was once under Inca control [2, 5]. One individual was a woman in her thirties, and the other was a young man of about 20 [1, 2]. Both individuals died during the first decades of Spanish colonization, roughly between 1520 and 1540 [1, 2].

Researchers determined the mummies are approximately 500 years old ^[1]. The DNA evidence shows the virus was not present in the New World prior to contact with Europeans, indicating the disease arrived via Spanish settlers and explorers [1, 2, 3]. This biological data aligns with historical accounts of the rapid population collapse among indigenous peoples following the arrival of the Spanish, a collapse driven largely by diseases to which native populations had no immunity.

Smallpox remained a global threat for centuries after its introduction to the Americas until it was eradicated worldwide in 1980 ^[4]. The recovery of these ancient genomes allows scientists to trace the evolution of the virus and understand how it spread across the Americas during the 16th century [1, 4].