One of my old supervisors had noticed this on his trips to China. Between the manners and the hygiene, the hinterlands were an adventure for him.
His tale of getting to and using a small latrine - on stilts - that served an entire factory was particularly entertaining.
Yep, people think of China as modern cities like Beijing and Shanghai, when in fact the majority of the population still live pretty much as they did a hundred years ago.
Yeah, it shouldn’t be a real surprised that so many really nasty bugs are birthed there.