It is true that he wrote that. Here is some more, from Rerum rusticarum libri III.
“Precautions must also be taken in the neighbourhood of swamps, both for the reasons given, and because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and there cause serious diseases. [...] See that the steading does not face in the direction from which the infected wind usually comes, and do not build in a hollow, but rather on elevated ground, as a well-ventilated place is more easily cleared if anything obnoxious is brought in. Furthermore, being exposed to the sun during the whole day, it is more wholesome, as any animalculae which are bred near by and brought in are either blown away or quickly die from the lack of humidity.”
Yes, and thank you for sharing this. As another fun fact- washing hands and sterilizing equipment before surgery is only about 150 years old. Before the late 1800’s, surgeons and doctors would touch all their patients with bare hands or the same gloves. Tools were used all day on patients and only cleaned at the end of the day. The poor state of medicine in those times was largely to do with how filthy it was- in fact many wanted to ban surgery because it was so dangerous. When Joseph Lister told doctors to wash their hands... many, especially American and British doctors, were outraged.
They felt it an insult, and an implication that they were unclean. Doctor was a high title and these were generally learned gentlemen who thought they were the paragons of human virtues. The idea they needed to wash their hands because they were filthy when doctors often were cleaner and more well groomed than most riled them up. The results of Listers “controversial” practices however was just too good to deny. An extreme decrease in amputations and fatalities- of which compound breaks of the bone were a common cause- was virtually eliminated. By the turn of the 1900’s most well established doctors had begun sterilization. Germ theory wasn’t widely accepted until the 1890’s when it really began to eclipse “miasma” theory, in fact they didn’t understand how or why the polio vaccine worked when they first began administering it!
I did read about that, actually, and interestingly, Ayurvedic doctors in India around 1000 AD had a smallpox vaccine and even theories as to why it worked.
Many years before my country (Nigeria) even existed, tribal wars were fought with biological weapons. As we learnt, the shamans always kept scrappings of smallpox scabs and made "tonics" from them. They claimed that the deities had blessed the tonics and made them into invulnerability potions. Warriors spent weeks fortifying themselves with the potions (they drank them). When it was time to fight, the tribes released powdered scabs into the air, typically upwind of their enemies. Soon, the enemies were dying of smallpox. The fear factor also helped. Now we know they were actually kinda vaccinating themselves with the tonics. It's always nice to see how we can arrive at the same place via different routes.
“Precautions must also be taken in the neighbourhood of swamps, both for the reasons given, and because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and there cause serious diseases. [...] See that the steading does not face in the direction from which the infected wind usually comes, and do not build in a hollow, but rather on elevated ground, as a well-ventilated place is more easily cleared if anything obnoxious is brought in. Furthermore, being exposed to the sun during the whole day, it is more wholesome, as any animalculae which are bred near by and brought in are either blown away or quickly die from the lack of humidity.”