The international risk which zoonotic diseases pose by accessing the type of relationship human’s have with animals, and illustrating how human destruction contributes to catalysing future pandemics. This article follows The International Risk Podcast’s recent episode with David Quammen which can be found here.
On 30th December 2019, the lab results from a patient showing flu-like symptoms read ‘SARS Coronavirus.’ Such a result led to a world-wide pandemic known as COVID-19 killing millions of people, leading to a global recession and changing the the landscape of health infrastructure. Coronavirus refers to a family of viruses that cause respiratory and intestinal illness in both humans and animals, as such belongs to a category of disease termed Zoonosis.
Zoonosis describes a disease which is transferable between animals and humans, humans to animals as well as animals to other animals. Once a disease has transferred from animal to human, taken hold and caused sickness, that is called zoonotic disease. At least 60%-70% of disease’s worldwide are zoonotic diseases, such as Ebola, Aids, SARS, Influenza, as they have come into existence in human health as a result of the transmission from the original animal host. Thus zoonotic diseases highlight the how interconnected humans are with other species, which some scientists claim to re-affirm Darwin’s truth: that humans are equal in nature and not above it. Over recent years zoonotic disease outbreaks and diagnosis have accelerated since the 1960’s.
Whilst every new zoonotic disease is originally seen as a mystery to its appearance, finding the origin of the disease requires heavy research and constant observation of both non-human species and humans. Animals that are the primary host of a disease are known as ‘reservoir hosts.’ Reservoir hosts host the pathogen’s that cause the disease, however the host itself is not threatened by the risk of falling ill to the disease as the disease and host have evolved to cohabit peacefully. When a zoonotic disease passes from animal to human, or animal to another animal, this is called a spillover.
Why are such spillovers occurring?
The cause of spillovers can be summarised by two points: human disruption and human activity.
Humans are disrupting the eco systems that animals have habituated in for hundreds of years, and for every single species of animal there is at least one unique form of virus (some scientists expect to at least 10). All human activity that promotes this disruption, (eg. logging) promotes an opportunity for disease to spill over from the reservoir hosts to humans. Once a zoonotic disease is able to infect a single human, they are able to adapt, evolve and shape for the disease’s survival to transmit from human to human and can travel quickly worldwide, as seen with COVID-19.
The connection between ecological destruction and the emergence of new pandemics and disease is nothing new. All human’s actions have consequences, including on the health of animals, health of eco systems and the health of other human beings. Some scientists refer to this as ‘one health.’ The increasing demand for ecological destruction resulting from globalisation has forced humans to come into contact with animals in an unnatural way. Habitat loss and forced migration of birds and mammals forces them into environments that have not before been exposed to the pathogens they host. Viruses themselves are a natural phenomenon, they can only replicate and complete their life cycle in cellular creatures, amist all biodiversity worldwide contain natural viruses. However the exposure to
Increased human activity adds to the acceleration of zoonotic diseases found. Before the 21st century, coronavirus itself caused little worry for scientists in regards to the threat on human life, as it was only responsible for mere mild cold-like symptoms. Such a perspective changed after 2002, when an outbreak of SARS in China was responsible for bringing a threat to human life. According to scientists, the responsibility for the development of SARS belonged to the increase in intensive farming due to the rising demand for the consumption of meat. Raising animals in such cramped conditions, where the environment of an animal’s blood, faeces and urine coated the floor provided the perfect space for a disease to develop and spread. As such the current increased global demand for meat as a protein source has led to mass factory farming which is attributed to other issues such as deforestation, but creates an environment for disease to breed.
Highlighting that the relationship between humans and animals is of the utmost importance to target when trying to reduce the risk of infectious disease, specifically the risk of future epidemics and pandemics. Such diseases are described as Zoonotic diseases: infectious diseases that are transmitted between non-human animals and humans. Zoonotic diseases specifically increase the risk of causing pandemics due to how they are easily transmissible, and humans have not had prior exposure to build up immunity to the disease.
In 2004 the WHO (World health Organisation),OIE (World Organisation for Animal Health) and FAO (Food and Agriculture Organisation) collaborated in releasing a report describing how the increase in meat is the first point for the biggest risk factor in the creation of zoonotic disease. Since then little progress on a global scale has been made to target what the food and pandemics report, produced by ProVeg International, as the single most risky human behaviour in relation to pandemics. Built into the use of intensive farming the use of antibiotics has become omnipresent. Medicated feeds used . Fluoroquinolone antibiotics are a form of medicine used to kill bacteria and fight infections, which the WHO have classified as ‘critically important in human medicine,’ has been used in poultry farming since 1995. Since the introduction of Fluoroquinolones in the factory farming of poultry, bacterial resistance has developed from zero to 18 percent. Thus demonstrating the rise in antibiotic resistant strains of bacteria has been produced from the intensive farming industry.
Antibiotic resistant strains of bacteria pose a bigger threat to the extensive damage a pandemic can cause.To tackle the threat of pandemics and antibiotic resistant bacteria there needs to be a global change to the infrastructure of the global food system by acknowledging the threat the factory farming industry brings.