Ancient sheep virus traced through DNA preserved in medieval manuscripts

A recent study published in Science Advances has analyzed animal DNA extracted from medieval manuscripts to trace the nearly 4,000-year history of the sheeppox virus. Sheeppox is a highly contagious disease that can cause significant mortality rates and damage to wool, meat, and milk yields in sheep herds. The researchers examined works such as the York Gospels and the Corpus Glossary of Corpus Christi College Cambridge, finding that infected animals were used in their production.

Study author Louis L Hôte explained that parchment can preserve animal pathogen DNA, suggesting that archives and libraries worldwide may contain genetic traces of past animal disease outbreaks. The researchers found that sheeppox has been affecting Eurasian sheep herds for at least three and a half millennia, and its genome has remained relatively stable over the last few millennia, unlike other pathogens like smallpox.