For thousands of years, cholera was largely kept in check by these two factors: humans on the whole were disinclined to knowingly consume each other’s excrement; and, on those rare occasions when they did accidentally ingest human waste, the cycle wasn’t likely to happen again, thus keeping the bacteria from finding a tipping point where it spread at ever-increasing rates through the population, the way more easily transmitted diseases, like influenza or smallpox, famously do.
