Collaborative public health measures, such as those adopted in a One Health approach, are needed to address the potential health impacts of bushfires, climate change and coronavirus pandemic.
The essay below, by Nicodemus Masila, was submitted for the National Public Health Think Tank Competition and has been selected by Croakey for publication. The competition is an initiative of the Students and Young Professionals in Public Health (SYPPH) Committee of the Public Health Association of Australia.
Nicodemus Masila writes:
Globally there has been massive unprecedented public health impacts resulting from climate change, bushfires and the coronavirus pandemic.
One of the major public health challenges arising from destruction of biodiversity due to climate change, bush fires, urbanisation, and encroachment to wildlife habitats is zoonotic diseases and their spill-over to humans.
Due to the inextricable link between human, animal and environmental health, a One Health approach is recommended for implementation in response to these global public health threats.
Climate change is being experienced globally, and its effects continue to negatively impact upon vulnerable human populations, a phenomenon that touches on social determinants of health.
Broad impacts
The impacts of climate change span different sectors including agriculture, water and irrigation, livestock, wildlife and human health. The extreme effects of climate change such as floods, drought, and heat waves cause direct and indirect public health emergencies that calls upon state emergency services to work collaboratively with public and environmental health sectors to safeguard human health and wellbeing.
More adverse weather events in terms of moderate temperatures and heavy rainfall due to the changing climate patterns is projected to result in, for example, higher mosquito populations and increased cases of Ross River fever in Australia.
Recurrent heat waves pose a health hazard especially to young children and to the elderly, particularly those in aged care facilities.
An assessment by the CSIRO on interactions between climate change and fire regimes show that climate change exacerbates occurrence of bushfires.
Bushfire risks
The impacts of wildfires in the Amazon rainforests and in Australia recently, have been enormous. From a public health perspective, animals are reservoirs of diverse pathogens and destruction of their habitats through bushfires imply that they move to different ecological niches hence moving infectious diseases with them.
This predisposes humans to zoonoses (diseases that can spread between animals and humans) such as animal influenza, salmonellosis and campylobacteriosis as a result of living in close proximity to and interaction with animals. For example, pet handling of captive/wild lizards predisposes one to Campylobacter spp.
Bushfire smoke also contains particulate matter and toxic gaseous compounds that have detrimental effect on human respiratory and cardiovascular systems.
Subsequent rainfall after bushfires may wash away contaminants such as ashes, polycyclic aromatic compounds (PAHs), arsenic, copper and chromium into natural water sources and rain water tanks thus posing a public health hazard to humans when used as potable water.
Coronavirus pandemic
Lastly the coronavirus pandemic has had enormous impact on almost all facets of our lives. While the source has not yet been definitively identified, studies link it to animal reservoirs especially the bat whose coronaviruses are 96% identical to SARS-COV-2 (causative agent of COVID-19), and disease spill-over to humans through probable intermediate hosts such as pangolin.
With the pandemic having awakened more discussions about One Health, the best we can make out of it is to embrace the approach, and do more in surveillance, diagnostics, prevention, building capacities and safeguarding the ecosystem particularly to keep animals where they belong (in animal habitats!).
One example of a collaborative approach applicable to managing zoonotic infections is the One Health concept. One Health is a multidisciplinary and holistic concept that recognizes interconnections of different components of ecological communities and the inextricable link between human, animal and environmental health through interfaces with food, livestock, wildlife and pathogens in the environment.
The approach has a long history and its use has been evolving over the years since 1855 when Rudolf Virchow coined the term ‘zoonoses’ to the recent launch of One Health European Joint Program in 2018.
One Health approach
Cognisant of the great impact that zoonotic diseases have on global health security, the US Centers for Disease Control and Prevention developed a One Health Zoonotic Disease Prioritization tool which brings together representatives from human, animal, wildlife and environment health sectors to prioritise the endemic and emerging zoonoses of greatest national concern in a country or region.
Additionally, the approach has gained popularity and support from the World Health Organisation, Food and Agricultural Organization of the United Nations and the OIE. The OIE Wildlife working group continues to provide appropriate guidelines that aim to address increasing risk of disease spill over from wildlife to humans and domestic animals through capture, handling, poorly regulated trade and consumption of wildlife.
Climate change, bushfire and the coronavirus pandemic are thus One Health issues due to the many facets of human, animal and environmental health and wellbeing that they all affect.
In this regard, implementation of a coordinated One Health approach would foster transdisciplinary collaboration, communication and sharing of resources, both financial and technical expertise, to help develop effective interventions that enhance health outcomes at the human-wildlife-livestock interface.
Having experienced first-hand the benefit of having a zoonotic disease unit in Kenya, One Health has been embraced in some low- and medium-income countries, yielding impressive outcomes.
Multisectoral collaboration of agricultural research (such as the Australian Centre for International Agricultural Research. which has been at the forefront on One Health), environmental health (best placed to assess critical control points from farm-to-fork supply chain), wildlife, international trade (Department of Foreign Affairs and Trade), human health, veterinary and experts in zoonotic transboundary diseases, through an holistic One Health approach, will undoubtedly keep Australians safer and healthier.
Nicodemus Masila is an international student studying a Master of Environmental Health (Australia Awards) at Flinders University. Masila is from Kenya where he works as a senior zoologist in a state corporation. Masila’s academic background is diverse, with BSc. zoology, tropical animal health and Environmental Impact Assessment/audit qualifications. He is passionate about interdisciplinary collaboration of human-animal-environmental health experts/sectors working through an emerging global health approach “One Health” to enhance health outcomes at the human-animal-environment interfaces.
