It's well known that imperial Romans tried to clean up Europeans' filthy habits, but the latest research suggests that such sanitation innovations actually helped spread parasites.

Roman innovations in sanitation technology weren't beneficial to public health, and actually had a slightly negative effect, according to the latest research. 
Well known for introducing toilets, sewage systems, aqueducts and other plumbing-related amenities to the European continent, it's long been assumed such advancements led to hygienic improvements. 
On the contrary, the study notes that intestinal parasites like roundworm, whipworm and dysentery increased during Roman administration.