On March 11th, the World Health Organisation (WHO) declared COVID-19 a pandemic. The world went into lockdown to try and control the virus and life as we knew it changed overnight.
The leading theory is that COVID-19 originated from a wildlife market in China- that is, a market that sells wild animals, alongside other food products, such as fruit, vegetables and poultry. These types of live animal markets put different species of animals into direct and indirect contact, facilitating cross-species virus transmission.
However, it is not just wildlife markets that pose a threat to human health. Scientists have warned that the intensive exploitation of animals, farmed and wild, globally, will be responsible for the next pandemic. Indeed, 75% of emerging infectious diseases (EIDs) originate from animals.
The intensive exploitation of animals is terrible for animal welfare. But, it will also likely be responsible for the next pandemic. We’ll explore why that is in this article, which has been produced with reference to The Humane Society’s excellent report, “An HIS report: The connection between animal agriculture, viral zoonoses, and global pandemics”. References for all statements and stats mentioned in this blog can be found in The Humane Society’s report.
The intensive farming of animals contributes significantly to the transmission of zoonotic viruses between animal species and from animal to human.
Confining large groups of animals to cramped facilities is a breeding ground for disease. Not only do factory farms have a greater potential virus load, due to the sheer number of animals that they confine, but close confinement also allows for the virus to pass between animals much easier.
Factory farms are a huge animal welfare issue. The animals reared there suffer from a wide range of health concerns, including stress from close confinement and their inability to perform natural behaviours, such as grazing and bonding with their young. These high levels of stress can weaken the animals’ immune systems and make them more susceptible to disease.
A 2013 review published in the Proceedings of the National Academy of Sciences found “strong evidence that modern farming practices and intensified systems can be linked to disease emergence and amplification.”
There is a significant link between the clearing of natural habitat for large scale animal agriculture operations and the emergence of new viruses. Globally, around 73% of deforestation in the tropics and subtropics is for farming: 40% is cleared for large scale industrial farms and 33% for local subsistence farming. Indeed, more land is cleared for animal agriculture than any other human activity.
As humans continue to encroach onto these biodiverse habitats, wild animals will be in increased contact with people and domestic animals, increasing the potential for disease transfer.
While the close confinement of hundreds of thousands of animals in factory farms amplifies the spread of disease within the farm, the geographic concentration of farms in the same area can spread the disease to other nearby farms.
Factory farms tend to be based in densely settled areas where agricultural land is plentiful. This means that various factory farms will often be situated in limited geographical areas, increasing the likelihood of diseases being passed to neighbouring farms by those working on, or visiting, the farm, such as delivery drivers or veterinarians.
Disease can also be spread through waste disposal, ventilation systems and the movement of infected animals from the site.
The global live export trade can rapidly transmit diseases across the world. Live animals are transported long distances, for rearing or slaughter, and suffer considerably on the journey. The long journey times, cramped conditions and lack of adequate food and water are very stressful for the animals. This stress can weaken their immune system, making them more susceptible to disease.
In 2019, 2,082 calves discarded by the dairy industry were exported to Spain for ‘fattening’ on journeys lasting up to 135 hours. Calf exports have now been halted by the Scottish Government after these journeys were found to be unlawful, but the export of other animals, such as sheep, continues.
Pigs are transported to Asia from Europe & North America, for their ‘improved’ genetics. Scientific studies have shown that the long-distance shipment of these animals in Asia had brought in the global swine influenza, which now circulate in pig populations there.
Live animal markets
Throughout Asia, wildlife markets are common. Vendors sell live wild animals, such as bats and snakes, alongside other food products, such as fruit, vegetables and poultry. The animals are packed in tight quarters along narrow aisles in often unsanitary conditions, forcing them into direct contact with one another.
The diversity in species of animals confined to these markets facilitates the transmission of virus between species. Again, as the welfare standards are so poor and the animals suffer from high levels of stress, the susceptibility of animals to catch disease is amplified. The movement of animals into and between markets creates networks of potentially contaminating interactions.
These markets are breeding grounds for disease. But not only that, they are also responsible for spreading viruses geographically, with the movement of live animals in and between markets.
Additionally, animal exhibitions and agricultural fairs also potentially risk spreading zoonotic diseases in the US. Several US states, including Michigan and Ohio, have documented hundreds of human cases of influenza A arising from agricultural fairs.
Potential pandemics originating from factory farming
The 2009 strand of avian flu, otherwise known as bird flu, is fatal in more than 50% of human cases. Research shows if the virus was to mutate into a form that was much easier to transmit between humans, it would become a significantly more serious global pandemic that COVID-19.
TheNipah virus (NiV), which was, in part, spread to humans through pig farming, has a fatality rate of more than 75% in human cases. This is currently no vaccine for the disease. It is not known for certain how the disease emerged, but the close proximity of fruit bats foraging beside intensive pig production facilities is thought to have facilitated the transmission. It has been suggested that if a novel strain develops where human-to-human transmission becomes much more likely, we would be facing the “most devastating pandemic.”
For almost the entire 20thcentury, pigs in North America had been infected by one subtype of influenza, known as the classical swine flu. But, in the 1990s, a new strand of the flu appeared, thought to have originated due to the increase stocking densities of pigs on industrialised farms. In 2017, a study confirmed that swine influenza viruses were indeed more prevalent in factory-style pig farms.
In 2009, a review article between US and UK scholars warned that as pigs can host influenza strains from both humans and birds they could create a new influenza virus, which would possibly lead to a pandemic. Just a month later, the world did face a new influenza pandemic. But it doesn’t stop there. The scholars didn’t just warn of a single pandemic, but rather multiple pandemics, even referencing a Southeast Asian ‘wet market’ as the most likely breeding ground for the next pandemic virus.
What can you do to help?
We are supporting World Animal Protection in asking the UK Government to call for a global wildlife trade ban at the G20 summit in November this year. They are asking the Government to introduce a new law to ban the import and export of wild animals and wild animal products in the UK. Please help to end animal suffering and Take Action Now to end the wildlife trade.