Sars, Mers, now this: we must think hard about how we farm animals that are known hosts of human coronaviruses

Two decades ago, a seminal study from the University of Edinburgh compiled a list of all known human infectious diseases. It found a total of 1,415 different human pathogens, and claimed that 61% were capable of spreading between humans and animals. Today, with the world put on hold by a deadly disease that seems likely to have spread first from bats to humans, we know the dangerous effects of such pathogens all too well.

The group of diseases that spread from animals to humans are collectively known as zoonoses. The term encompasses diseases such as measles, which first spread from cattle to humans thousands of years ago