Reduction of risk Alongside ensuring that we are ready to face the next pandemic, there are steps that Aotearoa New Zealand can take to reduce the likelihood of a pandemic beginning here or overseas.
Environmental risks The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), an organisation affiliated with the United Nations, has published a report on the links between pandemics and the environment. This report estimates that there are 1.7 million as yet ‘undiscovered’ viruses existing in birds and mammals, with at least 631,000 suspected as being able to infect humans. 196 The report outlines that the risk of pandemics is increasing rapidly, and that with at least five new diseases emerging every year in humans, there is a possibility of any one of these diseases meeting the conditions required to start a new pandemic. 197 Over 70 percent of emerging diseases (for example Zika or Ebola) and almost all pandemics (for example HIV/AIDS and influenza), have been caused by microbes usually found in animals but that can be transmitted to humans (scientifically known as zoonoses). 198, 199 This means that human behaviour that changes how we engage and relate to animals has the largest impact on the risks of developing a new pandemic. 200 In particular, it is estimated that 30 percent of emerging infectious diseases since 1960 have been due to land use changes, particularly deforestation for farming and urbanisation. 201 Land use changes have driven a loss in biodiversity and this loss can lead to increased risk of emerging diseases, where species who can adapt to human landscapes are also sometimes able to harbour zoonotic pathogens. 202 In particular, most animals involved in zoonotic events are domestic (livestock, domesticated wildlife and pets), logically reflecting their contact rates with humans. 203 Researchers note that eight variants of avian flu already exist that can infect and kill humans and are now regularly found in chicken factory farms globally, although not yet in Aotearoa New Zealand. 204 In 2013, the Food and Agriculture Organization of the United Nations noted: … a pathogen may turn into a hyper-virulent disease agent; in monocultures involving mass rearing of genetically identical animals that are selected for high feed conversion, an emerging hyper-virulent pathogen will rapidly spread within a flock or herd. 205 In 2020, there were close to 25 million chickens in chicken farms in Aotearoa New Zealand. 206 While conventional cages will be banned by 2022 (and the new colony cage environment provides 750 square centimetres per bird), nevertheless keeping animals penned in the same location triggers genetic changes in common bugs, for example, Campylobacter, which is fairly widespread in Aotearoa New Zealand’s poultry population. 207, 208, 209 Globally, there is an increasing demand for bovine milk and meat. 210 However, this demand encourages more intensive production (higher stocking rates of potentially genetically similar stock), meaning these animals have greater contact but also may lack the genetic diversity that would resist the spread of a potential disease (this is also known as the monoculture effect). 211, 212 This intensification of farming systems also results in increased fertiliser use and effluent (livestock waste). This can then foster potentially dangerous pathogens through the creation of nutrient-rich environments. 213 This may be of particular concern in Aotearoa New Zealand, with dairy cattle numbers increasing nationally from 3.4 million to 6.3 million between 1990 and 2019 (an increase of 82 percent). 214 Climate change has also been implicated in the emergence of new diseases. 215 For example, the tick-borne disease encephalitis (inflammation of the brain) causes around 2,500 cases a year in the European Union, with 95 percent of realised 216 infections requiring hospitalisation and an overall patient fatality ratio of 0.5 percent of patients. 217 Increasingly warm temperatures are increasing the risks of encephalitis by causing changes in the tick’s lifecycle. 218
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