Did Pangolin Trafficking Cause the Coronavirus Pandemic? – The New Yorker

As the Asian populations declined, African pangolins began flowing east in large quantities. Since early times, many peoples of sub-Saharan Africa have harvested pangolins, trapping the animals with snares, tracking them with dogs, or coming across them in the forest. The hunters traditionally consumed their catch or sold it into local bush-meat markets. Eventually, the meat became popular in cities, too, such as Libreville, in Gabon, and Yaound, in Cameroon, and that led to rising prices around the start of the twenty-first century. The scales mostly moved through the ports and airports of Nigeria and Cameroon to Asia, especially China and Vietnam.

I know were serving as a transit point, Olajumoke Morenikeji told me recently. Shes a zoologist, and a founderof the Pangolin Conservation Guild Nigeria. To judge from the thousands of kilograms of scales seized, she said, you cant have all that just coming from Nigeria.

Luc Evouna Embolo, an officer for TRAFFIC, an international network that monitors the wildlife trade, gave a similar account from Yaound. Increasingly, middlemen incite local people to collect pangolins from the field and sell to them. The middlemen sell to urban businessmen who illegally export the animals. A villager might get paid three thousand C.F.A. francs (roughly five dollars) for a pangolin that will be worth thirty dollars in Douala, Cameroons economic capital, and much more in China. In 2017, police made one seizure amounting to more than five tons of scales, for which two Chinese traffickers were arrested.

In late 2016, CITES had decided to make all international trade of wild-caught pangolins and their parts illegal, but the traffic continued. Its scope could now be gauged only from the fraction seized by customs officials and other national enforcement authorities or detected by non-governmental investigators. By one estimate, almost nine hundred thousand pangolins have been smuggled during the past two decades. Some were alive. Some were dead, peeled of scales and frozen gray. The scales were concealed in sacks or boxes within shipping containers, sometimes labelled as cashews, oyster shells, or scrap plastic. Those who track this commerce, such as Challender and Heinrich, say that pangolins seem to be the most heavily trafficked wild mammals in the world.

There is a vogue in urban China for ye wei, or wild tasteswildlife meat, supposedly imbued with healthful, invigorating properties. Some consumers cherish the notion that eating pangolin is a revered national tradition. But that notion has lately been challenged. Earlier this year, a Chinese journalist named Wufei Yu published an Op-Ed in the Times highlighting old texts that advise against consuming the flesh of certain wild animals, notably snakes, badgers, and pangolins. Yu found that in 652, during the Tang dynasty, an alchemist named Sun Simiao warned about lurking ailments in our stomachs. Dont eat the meat of pangolins, because it may trigger them and harm us. A millennium later, in a compendium of medical and herbal lore now considered foundational to T.C.M., the physician Li Shizhen cautioned that eating pangolin could lead to diarrhea, fever, and convulsions. Pangolin scales could be useful for medicines, Li Shizhen allowed, but beware the meat.

Zhou Jinfeng, a noted conservationist who heads the China Biodiversity Conservation and Green Development Foundation, in Beijing, added a caustic dismissal. Its not a matter of tradition, he told me by Skype. Its a matter of money.

And now, along with the traffic of pangolins into China, a new concern has arisen: the traffic of certain viruses. There was an unheeded signal last year. On March 24, 2019, the Guangdong Wildlife Rescue Center, in Guangzhou, took custody of twenty-one live Sunda pangolins that had been seized by customs police. Most of the animals were in bad health, with skin eruptions and in respiratory distress; sixteen died. Necropsies showed a pattern of swollen lungs containing frothy fluid, and in some cases a swollen liver and spleen. A trio of scientists based at a Guangzhou governmental laboratory and at the Guangzhou Zoo, led by Jin-Ping Chen, took tissue samples from eleven of the animals and searched for genomic evidence of viruses. They found signs of Sendai virus, harmless to people but known for causing illness in rodents. They also found fragments of coronaviruses, a family high on the watch list of viruses potentially dangerous to humans. Still, this was not big news when the Chen group published its report, on October 24th. The scientists noted that either Sendai or a coronavirus might have killed these pangolins, that further study could help with pangolin conservation, and that such viruses might be capable of crossing into other mammals.

Three months later, the word coronavirus carried a different ring. An initial small cluster of abnormal pneumonia cases had appeared in Wuhan, the capital of Hubei Province; soon the number had exploded to thousands, and the city was in lockdown; Chinese sources had revealed that a novel coronavirus was the cause of this disease; the first genome had been sequenced and released, by a Chinese team led by Yong-Zhen Zhang, of Fudan University, and with one Western partner, Edward C.Holmes, who arranged to make the sequence public on a Web site called Virological, run by a colleague at the University of Edinburgh; cases had started turning up elsewhere, including South Korea, Singapore, and the United States; the World Health Organization had declared a global health emergency; and everyone was now watching. Scientists who understand zoonotic diseasesthe diseases caused by pathogens that pass from nonhuman animals into humanshad begun asking, Which animal was the source? Everything comes from somewhere, and novel viruses come to people from wildlife, sometimes through an intermediary animal that may or may not be wild.

Bats were prime suspects, because the SARS virus that surfaced in 2002highly lethal and transmissible, but quickly contained by the middle of 2003had been a coronavirus hosted by bats. The MERS virus, which emerged on the Arabian Peninsula in 2012, even more lethal but less transmissible than SARS-CoV (as that first virus became known), was also a coronavirus traceable to bats, though in that case the bat virus had established itself in camels for some decades before spilling over into humans. Another notion about the new viruss host was snakesa suggestion made in late January, 2020, based on tenuous evidence, and quickly dismissed.

The attention swung back to bats on February 3rd, when a group led by Zheng-Li Shi, of the Wuhan Institute of Virology, presented genomic data showing a close similarity between the new virus and a coronavirus sequence they had found, half a dozen years earlier, among horseshoe bats in a mine shaft in Yunnan Province, a thousand miles southwest of Wuhan. The genome of this bat virus, now called RaTG13, was 96.2 per cent identical to the new human coronavirus. This was strong evidence that the new virus originally came from bats, but a four-per-cent difference between the genomes was far from a perfect match. Four per cent, in fact, implies decades of evolutionary divergence. Where had the new virus spent that timein what population of bats or other animalsand how had it spilled from one of them into its first human host? With those questions pending, another candidate for the intermediary emerged. On February 7th, the president of South China Agricultural University, in Guangzhou, declared at a press conference that a team from her institution, in work not yet published, had found what may be an intermediate host of the virus, bridging the gap between bats and humans: pangolins. According to a report by Xinhua, the official Chinese news agency, the pangolin virus that the researchers had investigated was a ninety-nine-per-cent match with the coronavirus showing up in people.

The announcement was an overstatement of what the researchers had found, but it caused a flurry of headlines. Even the CITES secretariat, based in Geneva, echoed the claim, tweeting the next day that #Pangolins may have spread #coronavirus to humans, and sugaring that sour tweet with video footage of cute pangolinsone of them a female with a juvenile on her backclimbing tree branches and snooping for ants. The implication was: these adorable animals carry lethal viruses, so best to leave them alone. When the study from South China Ag. went online, the big result was not quite as big as advertised, though it was still dramatic. The coronavirus genome that these researchers had assembled, from pangolin lung-tissue samples, contained some gene regions that were ninety-nine per cent similar to equivalent parts of the SARS-CoV-2 genomebut the over-all match wasnt that close. Maybe two coronaviruses had mergedin a single animal, the researchers wrote,and swapped sections of their genomesa recombination event. Such an event may even have proved fateful, by patching one genomic section of a pangolin coronavirus together with a bat coronavirus. That section, known as the receptor binding domain (R.B.D.), endowed the composite virus with an extraordinary capacity to seize and infect certain human cells, including some in the respiratory tract.

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Did Pangolin Trafficking Cause the Coronavirus Pandemic? - The New Yorker

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