Better than a ban: Preventing the next pandemic with stronger biosecurity at live animal markets

In light of the COVID-19 pandemic, a Chinese ban on trading with wildlife  has gained many supporters and advocates. However, the effectiveness of this ban for reducing disease transmission is doubtful.

Many local and indigenous communities eat bush meat: it is a tradition, a food security strategy and a means for income generation. While wildlife trade threatens animal welfare and the protection of endangered species, a ban is unlikely to cease the trade. On the contrary, a top-down-imposed wildlife trade could push this value chain into the black market where monitoring and control will be impossible. So, such a ban could actually elevate the risks of disease transmission.

Improving biosecurity at live animal and food markets offers a more practical and efficient way to control diseases and can kill several infections with one stone. In this article researchers from the Swedish University of Agricultural Science (SLU) and the National Veterinary Institute (SVA) outline a versatile biosecurity framework, going over preventative measures and considerations for their implementation.

What do infectious diseases like HIV/AIDS, Ebola, SARS and the recent COVID-19 have in common? They all originate from the animal kingdom.

Like 61% of all human infectious illnesses, these diseases are zoonotic, meaning they spread between animals and humans (or vice versa). The transmission pathways include consumption of meat, milk and eggs, or contact with body fluids, like blood

Recent development trends and expansion of human activities, including deforestation and bushmeat trade and consumption, have increased human contact with wildlife and thereby facilitated the emergence of new zoonotic diseases. Some of them, like those mentioned above, have caused malicious outbreaks with severe consequences to public health, livelihoods and the world economy.

The global trade in live animals is a multi-million-dollar industry. Billions of animals are traded annually across the globe, often in informal settings that are poorly monitored and controlled. Live animal markets serve as infection hubs where animals of different species and from distant regions are crowded together, sometimes in stressful conditions. Such circumstances create an optimal environment for pathogen exchange between animal species, as well as between animals and humans.

Evidently, limiting the opportunities for pathogen exchange between humans and animals is vital for reducing the risk of future emergence and outbreaks of zoonotic diseases. And that is where biosecurity measure can perform better than a ban.

Experience from many development projects suggests that achieving sustainable changes requires inclusive and voluntary participation of all the concerned stakeholders. These interventions also have to fit local socioeconomic and cultural context. Furthermore, disease control measures need to be attractive to all the actors involved in a value chain and provide tangible direct benefits, like the possibility to sell for a higher price if products are certified as safe.

Investing in people and offering tools that enable them to protect themselves and others is also critical. For example, educating people about the importance of hand washing is futile if water facilities are lacking. Similarly, informing market customers about risks related to consuming sick animals will have limited effect if consumers can’t afford to buy safer products.

Preventative measures to limit disease spread

Some actions that can improve biosecurity and reduce the risk of disease spread at live animal markets include:

• Provide access to basic hygiene facilities and clean water to wash hands, products, cages and other equipment. This will limit the risk of disease spread between animals, and protect both market workers and consumers.
• Ensure basic slaughter hygiene with the possibility to safely dispose of blood (which often contains the highest concentration of infectious agents) and offal, making sure that food items are not contaminated and that live animals cannot come in contact with the discarded material.
• Separate animals according to species in the marketplace. Reducing mixing decreases the risk for pathogen exchange. The importance of limiting interspecies contact has been illustrated during the COVID-19 pandemic – one theory is that the virus originated from bats and subsequently infected a second unknown species before humans.
• Take measures to improve animal welfare in trade. Reduced stress levels decrease disease transmission. This can be done by limiting crowding in cages and in pens, and by avoiding mixing animals that do not know each other.
• Set apart markets where animals are sold for recreational or breeding purposes from markets where animals are sold for slaughter and consumption and implement “no-out” policies at markets where animals are sold for slaughter. Markets, where animals are sold for recreation and breeding, should be under strict monitoring and control to avoid pathogen dispersal.

The above actions are relatively low-cost and possible to adopt in many different settings. There are also several measures that are more resource-demanding to implement and maintain. However, if enforced successfully, these actions can substantially limit the risk of disease dissemination. Some examples include:

• Establish and enforce health inspections of all animals that enter the markets. Refusing entry for animals that are displaying clinical signs of disease will minimize the spread of pathogens, both within and between species.
• Instate regular “rest days”, closing markets for cleaning and disinfection. For example, Hongkong started to close live bird markets for one day every month as a response to the avian influenza outbreak in 2001. On this rest day, all remaining birds were slaughtered and the market area was cleaned, which considerably limited the occurrence of avian influenza virus in the bird feces.

Considerations for implementation

The measures described above are relatively simple, but successful implementation is likely to raise challenges in many contexts. Live animal markets are common in low- and middle-income countries where infrastructure is often poor and corruption widespread. In these settings, access to training in animal and public health is limited, which translates into the lack of competent personnel for animal and food inspection.

Many markets are informal, which complicates monitoring. But while formalizing these markets is desirable from the biosecurity and public health standpoint, it is important to ensure that formalization does not lead to price increases. Otherwise, informal structures will quickly be re-established.

COVID-19 has demonstrated how sensitive and ill-prepared the world is for combatting pandemics. Demands and pressure for forceful actions are high. However, it is important that policy makers refrain from low hanging fruits that can generate media ovation, but don’t suit local realities and thus can’t be sustainable. Banning wildlife trade is exactly this kind of solution.

The argument for biosecurity does not favour wildlife trade, but rather emphasizes the key role of participation and community ownership in disease control. Any top-down imposed ban as such will not be sustainable for minimizing the risk for future pandemics.

Banning activities without having an agreement and buy-in from the people who are affected is counterproductive. On the other hand, sound biosecurity actions anchored in the participation of the actors concerned, will reduce pathogen transmission and ensure that people who depend on animal trade can continue to fulfill their economic goals without risking their and public health.

Written by Sara Lysholm, Maja Malmberg, Erika Chenais and Johanna Lindahl.

Sara Lysholm is a veterinarian and a PhD-student at the Division of Ruminant Medicine, Department of Clinical Sciences, at the Swedish University of Agricultural Sciences (SLU). Sara is researching infectious diseases in small ruminants in Zambia and Tanzania and has been working at small livestock markets in Zambia.

Maja Malmberg is a Researcher at the Section of Virology at the Department of Biomedical Sciences and Veterinary Public Health of the Swedish University of Agricultural Sciences (SLU). Focusing on molecular infection biology, Dr. Malmberg studies viruses found in wildlife, livestock and pets.

Erika Chenais is a veterinary epidemiologist at the National Veterinary Institute (SVA) with research focus on the infectious animal disease in low-income settings.

Johanna Lindahl is a veterinary epidemiologist and docent in infection biology, jointly appointed by SLU, Zoonosis Science Centre at Uppsala University, and International Livestock Research Institute, Nairobi, Kenya.