One health for our health

COVID-19 has highlighted the impact of humanity's changing relationship with the environment. Infectious disease expert Professor David Murdoch says a One Health approach is needed to help ward off future threats.

In late 2019, a new virus made the transition from animal to human. Within six months, COVID-19 had created a global pandemic, the lockdown of a third of the world's population and the deaths of hundreds of thousands of people worldwide.

While the ferocious impact of this new virus shocked many, the international infectious diseases community had been anticipating something like it for some time.

“COVID-19 is being referred to as a 'once in a 100-year event', but this terminology is misleading. A global pandemic was always a matter of 'when, not if' and COVID-19 won't be the last,'' says infectious disease expert and University of Otago, Christchurch Dean Professor David Murdoch.

“COVID-19 is one of hundreds of new infectious diseases that have emerged at the animal-human interface and the third major outbreak of a new coronavirus this century.”

Diseases such as COVID-19 that originate in animals are called zoonotic diseases, and include Ebola and the H1N1 strain of influenza dubbed swine 'flu by media. Murdoch says 60 per cent of known infectious diseases in humans originate in animals, as do 75 per cent of new or emerging ones such as COVID-19. The emergence or re-emergence of zoonotic diseases is not new. What has changed in the past few decades is human behaviour and how we interact with our environment and the animals who inhabit it.

“Increased urbanisation, overcrowded living conditions, increased global migration, and the increasing push of humans into animal habitat has created an environment that promotes the transmission of infections and made the COVID-19 pandemic possible.”

The idea that the health of humans and animals and the viability of ecosystems are inextricably linked is the basis of a concept known as One Health. In 2013, Murdoch and other New Zealand scientists founded the One Health Aotearoa (OHA) alliance. The alliance includes the University of Otago's medical school, Massey University's veterinary school, and the Institute of Environmental Science and Research. The now more-than-120-strong collection of scientists has become New Zealand's leading infectious diseases research, education and advocacy group. Many of its members have advised government during the COVID-19 crisis and are involved in crucial research projects on the virus.

“Increased urbanisation, overcrowded living conditions, increased global migration, and the increasing push of humans into animal habitat has created an environment that promotes the transmission of infections and made the COVID-19 pandemic possible.”

Murdoch says a One Health approach – which brings together expertise and experiences from a wide range of backgrounds – is ideally suited in the current situation.

“Understanding the complex systems that drive the spread of an infectious disease is essential for informing strategies to tackle it. This requires input from multiple disciplines and an awareness of what is happening globally. Consequently, professionals and researchers from a wide range of disciplines must work together and with communities and government to prevent and control the disease's impact at all levels.”

Murdoch says COVID-19 has thrust into focus the impact of humanity's changing relationship with the environment.

“The World Wide Fund for Nature recently released a report that highlights the links between humanity's impacts on ecosystems and biodiversity and the spread of diseases, and how the health of humans is intimately connected to animal and environmental health. They referenced the likely animal origin of COVID-19, like so many infectious diseases, and the environmental changes and human behaviour that has led to this global pandemic.”

Murdoch says this report stresses the urgent need for in-depth reflection on the relationship between humans and nature, the risks associated with current economic development pathways, and how we can better protect ourselves in future.

“Concurrently, The Lancet One Health Commission called for transdisciplinary collaboration to promote original thinking and generate solutions to complex health challenges. They stress how COVID-19 represents a critical pivot point in modern times that epitomises why recognition of the fundamental interconnectedness of humans, animals and their shared environment is key to ensuring the healthy and sustainable future of the planet.''

Murdoch says New Zealand needs to adopt the One Health approach to strengthen its defences against future infectious disease threats.

“Like many countries, we are not always well 'joined up' – which is vital for a co-ordinated and timely response. We allow scientists to work in silos, despite obvious overlapping interests and skillsets,'' he says.

“We need to strengthen capability in areas such as epidemiology, modelling and outbreak management, and build generic pandemic plans that are flexible enough to respond to all eventualities.

“New Zealand has a Centre of Research Excellence in plant biosecurity, but not in animal biosecurity or infectious diseases. We also need to better integrate science and research into the health system. This requires a culture change and investment so research is regarded as business-as-usual for district health boards, providing the science needed to inform policy, preparedness and best practice.”

Leadership is also essential, according to Murdoch. “We have seen good examples of science-informed responses to COVID-19 and the critical partnership of science and leadership. Yet we have historically lacked national leadership, investment and co-ordination in infectious diseases,'' he says.

“This is the ideal time for good leadership in science. We have seen this in the highest levels of government in New Zealand and we now need to see this at all levels moving forward to get us out of this pandemic in the best shape possible and to secure our future. Because this is going to happen again – and sooner than you think.”

Professor David Murdoch is one of three independent international experts who have been invited to advise the Oxford University COVID-19 vaccine development effort – regarded as one of the more likely to succeed in developing a vaccine against the virus. As a member of the trial steering committee, his role is to provide expert oversight on all aspects of clinical trials to test the vaccine's effectiveness.