YIKES! I always had this worry when doing my research but fortunately never ran into anything like this. I did question how I should be handling doctors’ notebooks from a smallpox hospital that looked like they hadn’t been opened in centuries, but luckily no scabs.
Ada PalmerHistorian friend was reading a civil war era letter in an archive, the letter said “In this envelope I include my smallpox scabs” and sure enough there they were. Had to call CDC for a hazmat team.