Podcast Summary
COVID-19's journey from animals to humans and back: COVID-19 originated in animals, spread to humans, and now spills back into wildlife, continuing to evolve and pose a risk to us.
COVID-19, which has greatly impacted humans, most likely originated in animals, specifically bats, and then spread to other animals and humans through a process called spillover. However, the story doesn't end there. Once the virus enters the animal population, it can continue to spread and evolve in a process called spillback. This was evident during the mink COVID outbreak in the United States, where mink farms, which house tens of thousands of animals in close quarters, became hotspots for the virus to spread among various species, including minks, cats, dogs, and even seagulls. The interactions between these species on mink farms provide even more opportunities for the virus to mutate and potentially re-enter the human population. The fact that COVID-19 is now spilling back into wildlife is a concerning stage in the journey of this pandemic, as it will continue to evolve out of our sight and control.
COVID-19 Impact on Mink Industry: Infections, Transmission, and Lack of Regulations: The COVID-19 pandemic has led to significant issues in the mink industry, including millions of infected and killed mink, increased risk of transmission to humans, and lack of regulations for farmers and workers.
The COVID-19 pandemic has led to a significant issue in the global mink industry, with millions of mink infected and killed, and the risk of transmission to humans through spillback. Mink farms, often colloqually referred to in derogatory terms, are not easily identifiable and do not require vaccinations, testing, or masking for workers or visitors. The farmer in the text described having mink die during the first wave of the pandemic, but they were not tested for COVID-19. The risk of infection and transmission is higher due to the increase in COVID-19 cases and anti-vaccine sentiment in nearby areas. The mink industry is facing challenges on multiple fronts, including animal welfare concerns, environmental issues, and now, the COVID-19 pandemic. The development of a vaccine for mink and other animals may help reduce disease, but it does not prevent infection or transmission. The farmer in the text did not wear a mask or ask about my vaccine status, highlighting the lack of regulations in the industry. The pandemic has brought attention to the concept of zoonotic diseases and the importance of understanding and mitigating the risks of spillover and spillback.
Impact of Pandemics on Animals: Spillback and Evolution of New Variants: Pandemics can impact animals by spilling over from humans to wildlife, creating new reservoirs and driving the evolution of novel variants. Controlling disease spread in animals is challenging due to their unpredictable behavior, as seen in COVID-19 outbreaks in mink farms.
Pandemics can have far-reaching impacts on both human and nonhuman animals when pathogens spill over and back between species. This process, known as spillback, can lead to epidemics in wild animals, including endangered species, and establish new wildlife reservoirs. These reservoirs can drive the evolution of novel variants that can pose new threats to humans. For instance, the unusual number of mutations in the Omicron variant of COVID-19 suggests it may have originated in a nonhuman animal. The American mink is a possible contender as it can contract the virus from humans and pass it along to both humans and nonhuman animals. However, controlling the spread of diseases in animals is much more challenging than in humans, as we have less control over their behavior. The COVID-19 outbreaks in mink farms in Europe illustrate this challenge, as containment efforts failed despite stringent measures. Spillbacks can confound our containment strategies and expand the reach of diseases in the natural world, making it crucial to understand the dynamics of disease transmission between species.
Underestimating interconnectedness between species hinders disease surveillance: Current disease surveillance systems prioritize reacting to large-scale die-offs and overlook the silent establishment of pathogens in new reservoir species, limiting our ability to detect and understand spillback phenomena. Holistic surveillance approaches are needed to account for the interconnectedness of different species.
Our current disease surveillance systems in the United States primarily focus on reacting to large-scale die-offs in wild animals and have limited funding for proactively searching for the silent establishment of pathogens in new reservoir species. This creates significant gaps in our ability to detect and understand the spillback phenomenon, where viruses can move between humans, wildlife, and domestic animals. The way we conceptualize and monitor the movement of pathogens can obscure their true nature, as we are all animals sharing a planet with permeable species boundaries. For example, morbillivirus, which causes measles in humans, has a complex history of jumping between cattle, humans, and dogs, demonstrating the interconnectedness of different species and the need for more holistic surveillance approaches.
Canine distemper spreads to various animals, causing harm and extinction threats: Canine distemper's spread to mink farms introduced a more difficult-to-control virus, Amdoparvovirus 1, causing widespread harm to wildlife and potentially humans, emphasizing the importance of biosecurity measures to prevent and contain outbreaks.
The spread of canine distemper in dogs led to the infection of various domesticated and wild animals, causing significant harm and even extinction threats. The mink industry's attempt to contain distemper inadvertently introduced a more difficult-to-control virus, Amdoparvovirus 1, which became a perpetual reservoir in mink farms and spilled back into the wild, infecting numerous species and potentially humans. The interconnectedness of animal populations and the ease with which pathogens can spread between them highlights the importance of biosecurity measures to prevent and contain outbreaks. The ongoing impact of these viruses on wildlife populations underscores the need for continued research and monitoring to mitigate the risks and protect endangered species.
Mink farming conditions contribute to coronavirus spread: Mink farming's high-density, poor sanitation environments increase coronavirus transmission and weaken immune systems, despite biosecurity measures not being consistently enforced.
The living conditions of mink in farming operations can contribute significantly to the spread of the coronavirus. Unlike humans, mink are kept in high-density environments with poor sanitation, making it easier for the virus to spread through respiratory transmission and contaminated feces. These conditions can also weaken their immune systems, making them more susceptible to infections. Despite the risks, biosecurity measures are not consistently enforced in mink farming operations in the US, increasing the likelihood of outbreaks. Additionally, due to their solitary nature and lack of domestication, mink are more vulnerable to pathogens and require frequent vaccinations. The industry's lack of regulatory oversight further exacerbates the risks associated with mink farming.
Impact of Coronavirus on Mink Farms and Wildlife: The coronavirus outbreak in mink farms led to the spread of the virus to wild animals and humans, highlighting the potential for zoonotic transmission. Despite efforts to contain the outbreak, the risk of susceptible species harboring the virus remains.
The coronavirus outbreak in mink farms in the United States and Europe had significant impacts on both farmed and wild animals, as well as on human health. Mink farmers in Utah were resistant to outside access for testing and quarantines, leading to potential spread of the virus. The USDA had no budget to prevent coronavirus from spreading on mink farms, unlike their efforts to combat avian influenza. The virus spread to wild mink and white-tailed deer, with studies detecting infection in 30% of deer samples and 1 in 3 white-tailed deer in Iowa having viral RNA. Coronavirus variants, such as the cluster 5 variant and the Michigan mink variant, emerged on mink farms and spread to humans, highlighting the potential for zoonotic transmission. Despite the subsiding of the outbreak at the end of the year, the risk of susceptible species harboring the virus remains. The broad range of species that can be infected by coronavirus, due to the essential ACE2 receptor, opens up possibilities for new modes of transmission and disease pathologies.
Viruses can spread from animals to other species, increasing the risk of new and dangerous variants: Viral spillbacks from animals to humans and other species can lead to new and potentially more dangerous variants, increasing the disruptive and dangerous impact of pandemics
The spread of viruses like COVID-19 is not a one-way process from animals to humans. Spillbacks, or the transfer of viruses from animals to other species, can expand the ecological opportunities for the virus and increase the likelihood of new and potentially more dangerous variants. For example, infected wild mink or deer can transmit the virus to humans through indirect contact, such as contaminated water or soil. These spillbacks can also lead to multi-species events, as shown in the history of coronaviruses that preceded COVID-19. The math and biology of these spillbacks can make the viruses more disruptive and dangerous for humans, as they can evolve and spread in new ways. The COVID-19 pandemic may already be an example of a multi-species event, and it's important to recognize the interconnectedness of viral spread between humans and animals.
