Will wet markets be hung out to dry after the pandemic? - Economist - Portugal
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WHEN ANTHONY FAUCI, a well-respected immunologist on President Donald Trump’s coronavirus task-force, called for the worldwide banning of wet markets last month, he may have had in mind somewhere like Tomohon in Indonesia. The highland town is surrounded by lush countryside in northern Sulawesi, home to the Minahasa people and an amazing diversity of wildlife.
Much of it makes its way to Tomohon’s covered market, where it is laid out on countless butchers’ slabs: warty pigs, flying foxes (actually, a fruit bat), reticulated pythons and the Sulawesi giant rat. Before feast days other specimens, all illegally caught, find their way to the stalls, among them the rare Celebes crested macaque, a large jet-black monkey, and the Sulawesi bear cuscus, a tree-dwelling marsupial. Domestic dogs in cages also wait their turn as traders with blow torches burn off slaughtered animals’ fur, setting their faces in a rictus grin. Even Minahasans revel in the market’s moniker: pasar extrim, the extreme market.
Dr Fauci is not alone in wanting wet markets banned. Scott Morrison, Australia’s prime minister, has called for their closure, as have American senators from both sides of the chamber. No wonder, you might think. It is not just the devastating effect they can have on a region’s biodiversity. Bustling markets selling live wild animals, often piled one atop the other, also give virologists the heebie-jeebies. Poor hygiene, animals kept in stressful conditions (which may affect their immune systems, making them more susceptible to disease) and traders and customers packed cheek-by-jowl can easily result in a “spillover” event, when a virus jumps from an animal into a human, causing a new disease, says Olivier Restif, a virologist at the University of Cambridge.
No one knows for sure whether the novel coronavirus got into humans in another live-animal market, this time in Wuhan, central China, the original centre of the covid-19 outbreak. It may have been an unhappy coincidence—any place that brings hundreds of humans together in close proximity has the potential to spread a disease. But many virologists think SARS-CoV-2, the virus that causes covid-19, originated in bats and then may have infected an intermediate species, possibly a pangolin, a scaly anteater prized for its meat and medicinal properties. What is undeniable is that Wuhan, in which live pangolins, civets and other wild species were sold, is exactly the sort of place where a new zoonotic disease might originate.
Mankind has fought several bitter battles against virulent enemies that emerged from live wild animals in wet markets, although such diseases’ exact sources are often murky. One of the most recent was SARS, another coronavirus that spread around the globe in 2003, which was believed to have been passed to locals through bats, via civets sold for meat in a marketplace in Guangdong, also in China. Wild animals are particularly dangerous because humans have not grown accustomed to—or conquered—their bugs, as they have with many domesticated species. Because viruses and the like are nearly always passed on via the faeces or urine of the infected creature, markets with scant hygiene—for example where animals are poorly butchered and the bladder is contaminated—pose the greatest risk.
Yet many virologists, including Mr Restif, do not want to see a blanket ban on wet markets. Rather, they prefer a more nuanced approach and more narrow regulation to control their most dangerous aspects. To understand why, it helps to unpick what wet markets are, and their role in the feeding of billions of people.
The term “wet markets” probably entered the English language via Hong Kong. It is, at its most basic, any grouping of vendors selling fresh goods. Markets are often watery because they are sluiced down, or because of the melting of the ice used to stop food from spoiling. The description contrasts with places that sell dry goods, such as rice and grains.
Wet markets come in many forms. They encompass both Tomohon and, for example, Chun Yeung Street in Hong Kong, which must adhere to stringent health guidelines and where the only live goods available are aquatic (fish are not considered a viable vector of such nasty diseases as covid-19, in part because they lack respiratory systems comparable to those of humans, which many viruses attack).
Between those extremes lies somewhere such as Kalerwe market in Kampala, Uganda’s capital. At first sight, it presents many of the risks associated with wildlife markets. Live chickens can spend three weeks in cramped cages before being sold, says Clovice Kankya, a biosecurity expert at Makerere University. A vendor will spend the whole day handling birds, cleaning their droppings and inhaling the same air. Zoonoses like brucellosis, a bacterial infection common in cattle, kill thousands of Ugandans each year, not least through infected meat. What is more, inspectors lack their own laboratories to do proper tests and unscrupulous traders hide suspect meat from their scrutiny.
But the risks from the market can be overstated. With the exception of chickens, which are sold live, most animals in Kampala’s market have been slaughtered in abattoirs, rather than freshly killed in the market. Cases of animal-to-human disease transmission in Uganda have happened “mainly in the village”, where beasts are slaughtered in homes without any inspections at all, says Winyi Kaboyo, a public-health expert. And although wild animals are eaten in the countryside, they tend not to be traded—openly at least—in cities.
Closing down wet markets would have wider implications. A study of 350 such markets in Nanjing, an urban area of 8m people in eastern China, found that they accounted for 80% of the city’s vegetable sales. Across the whole country it has been estimated that such places handle 73% of all the fresh vegetables and meat that is bought. In contrast, the study found that supermarkets tended to be where Nanjing’s households went to buy processed food. Were markets closed and locals pushed into supermarkets, says Zhengzhong Si of the University of Waterloo in Canada, one of the authors of the study, their health would inevitably suffer, as they would be more likely to pick processed meals over fresh produce. Mr Si found that the majority of households in his study bought vegetables at least five times a week—a rate attributed to the abundance of markets—but visited supermarkets much less often.
Wet markets in China owe their popularity to their several virtues. Compared with supermarkets, they are more likely to be within walking distance of people’s homes. They also tend to be cheaper. Competition between vendors selling similar goods ensures prices are more dynamic, reflecting demand. Prices also tend to be negotiable, particularly when the customer has a long-standing relationship with a seller. And some Chinese cities subsidise land for markets, in recognition of their important role in keeping locals fed and healthy, says Mr Si. This further helps sellers keep things cheap.
All of which means that rather than pushing for the wholesale banning of wet markets, many scientists are calling for a more subtle approach. The World Health Organisation (WHO) is working on a proposal to recommend suspending the sale of live wild mammals in marketplaces for food, but not live farmed creatures such as poultry and fish, which pose a lower risk and where controls can be introduced. While a ban is in place, says Peter Ben Embarek of the WHO, authorities can then assess the risks, and identify practices that are deemed safe.
Previous suggestions, made earlier this year by the WHO, to allow live-animal markets to continue have already created outrage, not least from Australia’s prime minister, who claimed to be “totally puzzled” by the idea. Plenty of people will continue to call for outright closures. A lot of non-Westerners view this as cultural deafness. “Chinese prefer to buy their food fresh—living. Western culture is more about frozen food,” says Simon Lee, of the Chinese University of Hong Kong. Plenty think a ban on wet markets would be absurd, adds Mr Si. “It is like Chinese people calling for a ban on supermarkets.”
A full ban would also threaten to throw up an unintended consequence. By forbidding the selling of live meat in places where it is a “strong part of its source of food or a cultural pull,” says Mr Restif, “it will just go to the black market, where there can be no regulation.” Mr Ben Embarak agrees. Alongside any ban on wildlife sales, he says, there is a need for better policing of hygiene standards and the type of live meat sold. Overseeing this in countries where the rule of law is weak will not be easy, he acknowledges. But a global programme of education—both for authorities and locals—might help. The lesson of recent pandemics, he says, is that “we can’t carry on doing the same thing we’ve done for centuries.”
China, for one, seems to be listening. It has made permanent a ban it put in place on the selling of all wild live animals (other than seafood) at its markets. Rules might also encompass a prohibition on their breeding for food even if they were slaughtered away from the market—although to much dismay, such regulation may not include beasts used in traditional medicines.
No matter how well-regulated wet markets are, it will not end the threat of zoonotic diseases. Their danger lurks wherever humans encroach on wild animals, whether through logging, the building of settlements or the hunting and selling of meat. But tighter oversight would at least go some way to reducing a big source of risk. With the stakes so high, both for those vulnerable to a future pandemic, and the billions who rely on markets for nutrition, a measured response will be welcome.
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