How we made the coronavirus pandemic

It may have started with a bat in a cave. But human activity set it loose

David Quammen

04.04.2020

The latest new virus that has captured the world’s horrified attention is known as “nCoV-2019.” The name, picked by the Chinese scientists who identified the virus, is short for “novel coronavirus of 2019”. It reflects the fact that the virus was first recognised to have infected humans late last year — in a seafood and live-animal market in Wuhan — and that it belongs to the coronavirus family, a notorious group. The SARS epidemic of 2002-3, which infected 8,098 people worldwide, killing 774, was caused by a coronavirus. So was the MERS outbreak that began in 2012 and still lingers.

Despite the new virus’s name though, nCoV-2019 isn’t as novel as you might think. Something like it was found years ago, in a cave in Yunnan, a province roughly 1,000 miles southwest of Wuhan, by perspicacious researchers who noted its existence with concern. The fast spread of nCoV-2019 is startling — but not unforeseeable. That the virus emerged from a nonhuman animal, probably a bat, and possibly after passing through another creature, may seem spooky — yet, it is utterly unsurprising to scientists.

One such scientist is Zheng-Li Shi, of the Wuhan Institute of Virology, a senior author of the draft paper that gave nCoV-2019 its name. It was Shi and her collaborators who, in 2005, showed that the SARS pathogen was a bat virus that had spilled over into people. Shi and her colleagues have been tracing coronaviruses in bats since then, warning that some of them are uniquely suited to cause human pandemics.

In a 2017 paper, they set out how they had found coronaviruses in multiple individuals of four different species of bats, including one called the intermediate horseshoe bat, because of the half-oval flap of skin protruding like a saucer around its nostrils. The genome of that virus is 96% identical to the Wuhan virus. And those two constitute a pair distinct from other known coronaviruses, including the one that causes SARS. In this sense, nCoV-2019 is novel — and possibly even more dangerous to humans than the other coronaviruses.

Peter Daszak, the president of EcoHealth Alliance, a private research organisation that focuses on the connections between human and wildlife health, is one of Shi’s long-time partners. “We’ve been raising the flag on these viruses for 15 years,” he told me. “Ever since SARS.” During the second study, the field team took blood samples from many Yunnanese people, about 400 of whom lived near the cave. Roughly 3% of them carried antibodies against SARS-related coronaviruses. “We don’t know if they were exposed as children or adults,” Daszak said. “But what it tells you is that these viruses are making the jump, repeatedly, from bats to humans.” In other words, this Wuhan emergency is no novel event. It’s part of a sequence of related contingencies that will stretch forward into the future as long as current circumstances persist.

Current circumstances include a perilous trade in wildlife for food, with supply chains stretching through Asia, Africa, the United States and elsewhere. That trade has now been outlawed in China, on a temporary basis; but it was outlawed also during SARS, then allowed to resume — with bats, civets, porcupines, turtles, bamboo rats, many kinds of birds and other animals piled together in markets such as the one in Wuhan. Current circumstances also include 7.6 billion hungry humans: some impoverished and desperate for protein; some affluent and empowered to travel every which way by airplane. These factors are unprecedented. No largebodied animal has ever been nearly so abundant as humans are now. And one consequence of that abundance, that power and the consequent ecological disturbances is increasing viral exchanges — first from animal to human, then human to human, sometimes on a pandemic scale.

We invade tropical forests and other wild landscapes, which harbour so many species of animals and plants — and within those creatures, so many unknown viruses. We cut the trees; we kill the animals or cage them and send them to markets. We disrupt ecosystems, and we shake viruses loose from their natural hosts. When that happens, they need a new host. Often, we are it.

We are faced with two mortal challenges. Short term: We must do everything we can to contain and extinguish this nCoV-2019 outbreak. Long term: We must remember, when the dust settles, that nCoV-2019 was not a novel event that befell us. It was — it is — part of a pattern of choices that we humans are making. THE NEW YORK TIMES

FOREWARNED: The consumption of civets, possibly infected by bats, caused 2002-03’s SARS outbreak

CAGED TOGETHER: Wet markets bring diverse animals and birds, from ducks to hens and wild birds of prey, in proximity, causing the transfer of dangerous pathogens