Thanks NonValueAdded, I've been "working on" a topic about the 19th c cholera outbreaks in Italy, which in Naples in 1884 alone killed thousands and resulted in the ultimate abandonment of their Roman-era water supply. It should be noted that at the time, it had been a while since the Romans had sent maintenance crews, also more to the point, Naples wasn't the only place in Europe to get hammered (with the cholera, I mean). Although this is a topic of modern history, looks like a good choice for the weekly Digest ping as well.
It’s getting lost as ancient history, but the biggest strides taken to control infectious diseases were building a safe water supply and sanitary sewers. There are places in the Third World where those are still badly needed.