By Shruti Patel and Simon Gottwalt, Biovision
The number of new infectious diseases transmitted from animals to humans like SARS, MERS and COVID-19 has increased dramatically in the last few decades. Not only are there more types of diseases, the frequency of disease outbreaks is also rising.
Underlying this alarming trend are three key drivers: rapid urbanisation, expanding global mobility, and greater contact between humans and animals. The destruction of natural habitats, a stark increase in intensive livestock farming, and growth of wildlife markets make it easier for pathogens to jump from animals to humans. Indeed, scientists believe the new coronavirus, SARS-CoV-2 was transmitted from bats to pangolins that were subsequently sold in Chinese markets frequented by consumers.
Lost amidst calls to ban the sale of wild animals for consumption, many of the principles which govern food production today – a singular focus on productivity, widespread neglect of ecosystem services, and the poor treatment of animals – are an integral part of the problem.
Destruction of natural habitats
Half of the world’s habitable land is used for agriculture. Huge swathes are used for fuel production and livestock, posing a major threat to the environment and biodiversity. Palm oil monocultures for example, are a major driver of deforestation. In some regions, traditional farming methods that support biodiversity are being replaced by intensive production models. Encroachment into natural habitats increases the likelihood of humans coming into close contact with wildlife – the primary source of many emerging viral diseases. Furthermore, evidence suggests that the loss of biodiversity within these habitats increases the chances of pathogens jumping from animals to humans. Keeping biodiversity and habitats intact is therefore key to the prevention of future pandemics.
In highly populated areas however, research suggests that high levels of biological diversity are a strong predictor for the emergence of disease. In the pastoral areas of East Africa for example, humans, livestock and wildlife share the same habitat, making these populations particularly vulnerable to disease outbreaks. Here, early warning systems that detect outbreaks in animals before widespread transmission to humans play an important role in the sustainable management of the entire agro-ecosystem (see box).
Intensive livestock keeping is a major risk
As countries urbanise and citizens become wealthier, the demand for meat and dairy products is increasing. This has led to the rapid expansion of intensive livestock production systems. Genetically similar animals are often stressed by being kept in tight spaces under unhygienic conditions, leading to the suffering and ill-health of the animals, and creating ideal incubators for new pathogens. In addition, the rampant and heavy use of antibiotics in animals makes pathogens resistant to drugs also used in human medicine. Some experts forecast that by 2050, the rise of resistant bacteria could cause 10 million human deaths a year worldwide. Providing adequate nutrition, husbandry and housing for livestock is therefore not only critical for the welfare of animals and their productivity, it is integral to human health.
Solutions exist for managing the complex interactions between agriculture, infectious diseases, and human health. Consumers – especially those with the privilege of choosing what they eat – play a critical role in demanding more sustainably produced food, cutting down on animal products, and reducing food waste. Such changes can drastically reduce agriculture’s need for more land, and play a vital role in building a food system that puts less stress on the planet and on public health.
On the production side, steps to incorporate the environmental and health costs of industrial agriculture into decisionmaking can help shift production patterns, and approaches like agroecology which reconcile the conflict between land use, food production and habitat conservation can build food systems which serve both people and the planet. Around the world, there are many examples of such techniques and strategies being effectively used to build more resilient and healthy food systems (ref. Beacons of Hope); the challenge is to bring them to scale.