I think this Roman parasite problem probably got wiped out.
Literally!
I imagine the Roman use of elevated aquaducts helped provide cleaner water to Roman cities, only bird parasites to worry about in many cases. On the other hand, even now there are dangers. In Oaxaca my husband was leaning over a parapet in the elevated ruin there puking miserably. He had eaten chicken the evening before. Thankfully I must have eaten something else. When we returned to the hotel we asked to see the refrigerator where they said they had kept this chicken. Temperature was almost 50 degrees.