Problems within our global and interconnected food systems can result in outbreaks of infectious disease spread by bacteria, viruses, or parasites from non-human animals to humans. This is also known as zoonosis. The swine flu pandemic of 2009, for example, was caused by a hybrid human/pig/bird flu virus that originated from dense factory farms where pigs and poultry were raised in extremely cramped conditions together. Methicillin-resistant staphylococcus aureus (MRSA), a bacteria that results in more deaths in the US than HIV/AIDS, also has strong causal link to factory pig farms.
SARS-CoV-2, the virus behind the current COVID19 pandemic, may have developed in bats and later pangolins. Both species are regularly hunted for food and medicinal purposes and are sold in wet markets. Wet markets, where live animals comingle in unsanitary conditions provide the perfect environment for diseases to migrate between animals and people. Zoonosis is just one of the many threats posed by the expansion of our food system to global public health.
Globally, 72% of poultry, and 55% of pork production come from concentrated animal feeding operations (CAFOs), or factory farms. For example, chicken CAFOs can hold up over 125,000 chickens. The close quarters and high population inside CAFOs allow the sharing of pathogens between animals with weakened immune systems. Thus, diseases spread rapidly.
To safeguard their stock, CAFOs inject low doses of antibiotics into feed. This is intended to lower chances of infection, and conserve the energy animals expend to fight off bacteria in order to promote growth. This method is not without problems; antibiotics are usually administered to whole herds of animals in feed or water, which makes it impossible to ensure that every single animal receives a sufficient dose of the drug. Additionally, farms rarely use diagnostic tests to check whether they are using the right kind of antibiotic. Thus, every time an antibiotic is administered, there is a chance that bacteria develop resistance to it. Resistant bacteria can then pass from animals to humans via the food chain, or be washed into rivers and lakes. Also, bacteria can interact in the farm or in the environment, exchanging genetic information, thus increasing the pool of bacteria that is resistant to once-powerful antibiotics. Due to global trade of meat and animal products, these resistant bacteria can spread rapidly across the globe.
A study sampling chicken, beef, turkey, and pork meat from 200 US supermarkets found 20% of samples contained Salmonella, with 84% of those resistant to at least one antibiotic. Another study tested 136 beef, poultry and pork samples from 36 US supermarkets and found that 25% tested positive for resistant bacteria MRSA. Fortunately, in both cases these bacteria can be eliminated with thorough cooking. Nevertheless, more than 2.8 million antibiotic-resistant infections occur in the U.S annually, resulting in more than 35 000 deaths.
While antibiotic resistance has been a known issue for some time, policy responses have been mixed. The European Union has prohibited the use of antibiotics to promote growth in animals since 2016. Other parts of the world have been more lax, with nearly 80% of all the antibiotics dispensed in the US fed to livestock, and only 20% on humans. Here at home in Australia, we have one of the most conservative approaches, ranked the 5th lowest for antibiotic use in agriculture among the 29 countries examined.
The factory farm system is a modern answer to a modern problem -the rapid rise in global population and demand for meat. While the economies of scale allow factory farms to be more cost-efficient and more competitive in a very crowded market, these come at the expense of every other living thing involved. Further, as our demand for meat is projected to continue rising, so will the issues associated with factory farms: environmental damage from toxic waste pollution, poor animal welfare, the exacerbation of climate change, and poor working conditions. Last year, US Senator Cory Booker unveiled the US Farm System Reform Act of 2019. One proposal from the Bill is to shut down large industrial animal operations like CAFOs. While the Bill is unlikely to pass the Republican-controlled Senate and White House, it signifies the growing public awareness of the wide-ranging problems associated with our food systems.
Reducing our meat consumption also comes with personal health benefits, and reduces animal suffering, in addition to reducing the demand for factory farming and the associated health risks. That is not to say a change in dietary habit is without its barriers. Factors such as socio-economic status, access to food, and existing health problems will prevent many from drastically reducing their meat consumption. At the end of the day, our best is all we can do, but as more of us begin taking steps, however small, towards changing our diets, we will make a difference.
- By Hannibal Thai
*Special thanks to Ruby Green for her assistance in the writing of this post.
All researchers in the Social Change Lab contribute to the "Do Good" blog. Click the author's name at the bottom of any post to learn more about their research or get in touch.
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