At least 60% of infectious, 75% of 'emerging' diseases originate from animals, says study

The novel coronavirus, which has killed tens of thousands and turned the world upside down, is believed to have emerged in a wet market in the central Chinese city of Wuhan late last year.

Scientists think it originated in bats and could have been passed on via another mammal like a pangolin.

But whether from a bat or a pangolin, the deadly virus originated from the animal world, adding to the list of 'zoonoses' -- the name given to diseases transmitted from animals to humans.

They are not new -- tuberculosis, rabies, toxoplasmosis, dengue, malaria, to name just a few, are all zoonoses.

Beyond the current outbreak of coronavirus, IPBES estimates that zoonoses kill some 7,00,000 people a year.

According to the UN Environment Programme (UNEP), 60 per cent of human infectious diseases originate from animals.

The figure climbs to 75 per cent for "emerging" diseases such as Ebola, HIV, avian flu, Zika, or SARS, another type of coronavirus.

"The emergence of zoonotic diseases is often associated with environmental changes or ecological disturbances, such as agricultural intensification and human settlement, or encroachments into forests and other habitats," said a 2016 UNEP report.

"Changes in the environment are usually the result of human activities, ranging from land use change to climate change."

Domesticated animals are often a "bridge" between pathogens from the wild and humans.

Researchers have yet to come up with a definitive answer on how the virus migrates to people. The only sure thing, however, is that human activity facilitates the jump.

A study by American researchers published last week and completed before the new coronavirus outbreak identifies rodents, primates and bats as hosts of three-quarters of viruses transmitted to humans.

But domestic animals also carry about 50 per cent of the zoonoses identified.

In terms of endangered wildlife, the study shows that those who share the most viruses with humans are precisely "populations declining due to exploitation and loss of habitat".

The 2016 UNEP report, which noted that "ecosystem integrity underlines human health and development", said effective strategies already exist to control most neglected zoonoses. The main constraint, however, appeared to be "lack of investment".