16 Pandemics
16.1 Loss of habitat as a driver
Som text on the linksbetween loss of biodiversity and pandemics
Almost all pandemics start with a single infection event. For zoonoses from wildlife, this is a person, or group of people that made contact with an animal infected by a pathogen that infects them, replicates in their cells and then is transmitted to others. Surveillance data suggest that spillover events happen frequently around the world, but most infections are unable to cause further transmission among people. Sometimes, pathogens spill over and are able to transmit to a handful of people, undergoing a few cycles of transmission before the outbreak dies out. Where pathogens spread into dense human communities (e.g. COVID-19 within the live animal market and city of Wuhan 10 ), and when they are able to easily transmit from person-to-person, they can become pandemics. Preventing pandemics will require efforts to reduce the risk each of these stages occurring, through measures that diminish the underlying drivers of spillover, their spread among people and their ability to move globally through rapidly urbanizing landscapes, megacities and travel and trade networks.
Pandemics represent an existential threat to the health and welfare of people across the planet, and their emergence, impact and control are deeply embedded in biodiversity and the major causes of biodiversity loss. New diseases emerge largely in tropical or subtropical countries with high wildlife biodiversity. The first people to be infected are often from communities in remote or rural regions, in developing countries with lower capacity to rapidly diagnose and treat novel diseases, and control and contain pandemic spread. Land use change and the wildlife trade (especially unsustainable, illegal or poorly regulated wildlife trade) are key drivers of pandemic emergence, including the recent emergence of COVID-19. Pandemics, such as COVID-19, underscore both the indivisible interconnectedness of the world community and the rising threat posed by global inequality to the health, wellbeing and security of all people: Exponential growth in consumption of products from land use change and globalized trade, often driven by developed countries, have led to the repeated emergence of diseases from developing countries with high biodiversity, and thus conditions that increase potential for zoonotic emergence.
16.1.1 Bats habitat loss drives diseases
Many of the recently emerging highly virulent zoonotic diseases have a likely bat origin, for example Hendra, Nipah, Ebola and diseases caused by coronaviruses. Presumably because of their long history of coevolution, most of these viruses remain subclinical in bats, but have the potential to cause severe illnesses in domestic and wildlife animals and also humans.
Increasing numbers of breakouts of zoonotic viral diseases among humans and livestock have mainly been accounted to human encroachment into natural habitat, as well as agricultural intensification, deforestation and bushmeat consumption. Persecution of bats, including the destruction of their roosts and culling of whole colonies, has led not only to declines of protected bat species, but also to an increase in virus prevalence in some of these populations.
16.2 Apolitical Public Health
Memo
Global health is a discipline that holds within itself a deep contradiction—global health was birthed in supremacy, but its mission is to reduce or eliminate inequities globally.
Most epidemiological analyses and modeling studies to be devoid of any analyses of power. “For the most part, epidemiology as a method of science is considered apolitical; it actually serves as an ideological apparatus of imperialism by shielding structural causes of health inequities in the Global South,”
Epidemiological analyses of disease dynamics that fail to consider sociohistorical forces. In doing so, these studies end up diverting the public’s gaze from legacies of colonialism, white supremacy, structural adjustment, institutional racism, and purposeful under-development which leaves health systems so weak and ineffective.
Move away from the notion of a universal truth. Reject the notion that social inquiry can produce objective, value-neutral, and univocal understanding. Instead, we must embrace the critical and the polyvocal.
16.3 Pandemic Risk Management
Memo
We are dealing with an extreme fat-tailed process owing to an increased connectivity, which increases the spreading in a nonlinear way. Fat tailed processeshave special attributes, making conventional risk-management approaches inadequate.
The general (non-naive) precautionary principle delineates conditions where actions must be taken to reduce risk of ruin, and traditional cost-benefit analyses must not be used. These are ruin problems where, over time, exposure to tail events leads to a certain eventual extinction. While there is a very high probability for humanity surviving a single such event, over time, there is eventually zero probability of surviving repeated exposures to such events. While repeated risks can be taken by individuals with a limited life expectancy, ruin exposures must never be taken at the systemic and collective level. In technical terms, the precautionary principle applies when traditional statistical averages are invalid because risks are not ergodic.
Estimates of the virus’s reproductive ratio $R_{0} - the number of cases one case generates on average over the course of its infectious period in an otherwise uninfected population - are biased downwards. This property comes from fat-tailedness [4] due to individual ‘superspreader’ events. Simply, R 0 is estimated from an average which takes longer to converge as it is itself a fat-tailed variable
Standard individual-scale policy approaches such as isolation, contact tracing and monitoring are rapidly (computationally) overwhelmed in the face of mass infection, and thus also cannot be relied upon to stop a pandemic. Multi- scale population approaches including drastically pruning con- tact networks using collective boundaries and social behavior change, and community self-monitoring, are essential. Together, these observations lead to the necessity of a precautionary approach to current and potential pandemic outbreaks that must include constraining mobility patterns in the early stages of an outbreak, especially when little is known about the true parameters of the pathogen. It will cost something to reduce mobility in the short term, but to fail do so will eventually cost everything—if not from this event, then one in the future. Outbreaks are inevitable, but an appropriately precautionary response can mitigate systemic risk to the globe at large. But policy- and decision-makers must act swiftly and avoid the fallacy that to have an appropriate respect for uncertainty in the face of possible irreversible catastrophe amounts to “paranoia,” or the converse a belief that nothing can be done.