Wet market ban not enough, human interactions with animals must change to prevent another pandemic: Experts

As per experts, simplistic measures such as bans can be difficult to implement, so they must be carefully planned to prevent the proliferation of illegal trade


                            Wet market ban not enough, human interactions with animals must change to prevent another pandemic: Experts
(Getty Images)

Well-meaning but radical actions such as complete bans on hunting and wildlife trade, wet markets, or consumption of wild animals may be not be achievable and are not enough to prevent another deadly pandemic such as Covid-19, according to an international team of wildlife and veterinary experts. Instead, researchers have identified seven routes by which pandemics could occur and 161 options for reducing the risk, concluding that widespread and dramatic changes to the way humans interact with wild and farmed animals are needed. Solutions that only address one issue – such as trading of wild animals – are not enough, says the team led by the University of Cambridge. 

“Wild animals aren’t the problem, they don’t cause disease emergence. People do. At the root of the problem is human behavior, so changing this provides the solution,” says co-author of the study, Professor Andrew Cunningham, Deputy Director of Science at the Zoological Society of London, in the analysis. The report is currently being peer-reviewed. Some of the ways to reduce the risk of another pandemic are relatively simple, such as encouraging smallholder farmers to keep chickens or ducks away from people. Others, like improving biosecurity and introducing adequate veterinary and hygiene standards for farmed animals across the world, would require significant financial investment on a global scale.

Laws to prevent the mixing of different wild animals or the mixing of wild and domestic animals during transport and at markets, increasing switching to plant-based foods to reduce consumption of, and demand for, animal products, safety protocols for caving in areas with high bat density, such as the use of waterproof coveralls and masks, and improving animal health on farms by limiting stocking densities and ensuring high standards of veterinary care, are some of the suggestions.

The team emphasizes that simplistic measures such as bans can be difficult to implement, so they must be carefully planned to prevent the proliferation of illegal trade, or alienation and increasing hardship for local communities across the world who depend on wild animals as food. “A lot of recent campaigns have focused on banning the trade of wild animals, and dealing with wild animal trade is really important yet it’s only one of many potential routes of infection. We should not assume the next pandemic will arise in the same way as Covid-19. We need to be acting on a wider scale to reduce the risk,” says Professor William Sutherland in the University of Cambridge’s Department of Zoology and the BioRISC Research Initiative at St Catharine’s College, Cambridge, who led the research.

Limiting stocking densities and ensuring high standards of veterinary care on animal farms are options listed by the experts to reduce disease transmission risk (Getty Images)

The study considered all major ways that diseases with high potential for human to human transmission can jump from animals to humans (termed zoonotic diseases). The analysis says that zoonotic diseases of epidemic potential can also transmit from farmed wildlife (such as civets) and domesticated animals (exemplified by swine flu and avian flu), with greater risks occurring where humans, livestock, and wildlife closely interact. According to the researchers, potential ways another human pandemic could arise include wildlife farming, transport, trade and consumption, international or long-distance trade of livestock, international trade of exotic animals for pets, increased human encroachment into wildlife habitats, antimicrobial resistance, especially concerning intensive farming and pollution, and bioterrorism. The authors say that dealing with such a complicated mix of potential sources of infection requires widespread changes to the ways humans and animals interact. 

Scientists from across the world are trying to identify the source of the novel coronavirus. Some have said that it is likely that the SARS-COV-2, the virus which causes the Covid-19 disease, was passed from bats to a mystery animal species that then passed it on to humans. Initial reports also said that Covid-19 may have emerged from a Wuhan wet market, but others have challenged it. The research team included all categories of animals – wildlife, captive, feral, and domestic – in the study. The focus was on diseases, particularly viruses, which could rapidly become epidemics through high rates of human-to-human transmission once they have jumped from an animal. This excludes some well-known zoonotic diseases such as rabies and Lyme disease that require continuous transmission from animals.

According to the team, they have not proposed a list of recommendations for targeted agencies to respond to, but a set of options targeted at practitioners and policymakers to encourage “careful examination” of possible courses of action, their future testing, and the documenting of outcomes. “We can’t completely prevent further pandemics, but there is a range of options that can substantially reduce the risk. Most zoonotic pathogens are not capable of sustained human-to-human transmission, but some can cause major epidemics. Preventing their transfer to humans is a major challenge for society and also a priority for protecting public health,” says lead author of the study Dr Silviu Petrovan, a veterinarian and wildlife expert from the University of Cambridge.

Options need to be assessed for the local context of implementation, including those for their broader implications for the local human communities potentially affected, researchers explain. “When deciding on which measures should be adopted, policymakers and practitioners should first determine the context, the pathways of zoonotic disease transfer to be addressed, and the risks associated with them,” says the team. 

 

According to experts, potential ways another human pandemic could arise include wildlife farming, transport, trade and consumption, international or long-distance trade of livestock, and international trade of exotic animals for pets, among others (Getty Images)

The report says that supply-side interventions to prevent zoonotic emergence from wildlife may focus on preventing hunting and collection of high-risk species entirely (area-based or species-based restrictions), controlling the rate of hunting and collection through limits to numbers or specific characteristics of the animals taken, or regulating the hunting, consolidation, and trade through enforced standards. For livestock, supply-side interventions to prevent zoonotic emergence may focus on improving animal health and immune function in farms by limiting density and ensuring veterinary care, and preventing the mixing of domesticated and wild-sourced or farmed wildlife animals in farms, says the study. The researchers suggest improving the biosecurity of farming practices, by using disposable protective clothing and the introduction of health surveillance for farmworkers. 

To reduce the risk of disease transmission during transport, the team calls for banning long-distance and/or cross-border transport of high-risk species, or increasing enforcement and penalties for these activities if they are already restricted. “Ban the international transport of live wild animals except for licensed conservation and scientific programs. Introduce mandatory quarantine for all exported live wildlife and domestic animals to destination countries to prevent diseases from crossing borders. Regulate maximum animal density being simultaneously housed or transported,” they add.

To change consumer behavior, they suggest banning the purchase, sale, possession, or use of high-risk products. “Establish or increase penalties for the purchase, sale, or use of high-risk products. Influence consumer attitudes to increase the acceptability of lower-risk substitute products, such as plants or synthetic substitutes for food, clothing, or medicine instead of animal products, particularly those from high-risk species,” the findings state. 

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