Sanitation systems are really old, though.

I was impressed with the sophistication of the one present in Glanum, a small (but wealthy) Roman provincial town abandoned in the 2nd century. The sewer system runs underneath the main street: baths, villas, and the abatoir connect to it.

To say nothing of the ones in major cities of the time.

That doesn't mesh with my experience. When I moved from the UK - where windows open outwards and its not really possible to have screens - to the countryside in mainland Europe where mosquitoes and flies are much more common, one can buy mosquito nets for windows from the supermarkets. I don't regret that purchasing decision at all - being able to have the window open at night in summer means I can actually get some sleep :)