While the small pox/disease ridden blankets may or may not be factual, there is plenty of historical records predating Europeans landing in the Americas of using disease in warfare.
When sieging cities in antiquity water supplies would be contaminated. Arrow heads be smeared with poison and otherwise feces to cause infections. In Europe during Middle Ages corpses and feces of diseased would be catipulted into cities to cause infection, notably this this even happened with corpses that died of the bubonic plague.
When sieging cities in antiquity water supplies would be contaminated. Arrow heads be smeared with poison and otherwise feces to cause infections. In Europe during Middle Ages corpses and feces of diseased would be catipulted into cities to cause infection, notably this this even happened with corpses that died of the bubonic plague.