A future of infectious disease

Since the first decade of the 21^st century public health specialists and the WHO have warned us about the possible outbreak and spread of a new virulent infectious disease once referred to as Disease X by the WHO.

Despite what we might believe and despite the many advances in medicine and public health, epidemics and pandemics of infectious disease continue to remain a critical threat to our health.

Before the advent of Coronavirus many believed that we had won the battle against bacterial and viral infections and had little to fear. As Coronavirus has demonstrated, nothing could be further from the truth.

But more than that, over the last 20 or so years we have tended to overlook major outbreaks of infectious disease such as Ebola and Dengue as well as the resurgence of a raft of childhood infections such as measles.

So why have we been so confident that infectious disease is no longer a global threat particularly when bacteria and viruses have been an important part of our world for millions of years much longer than we have been around?

In all of this we continue to overlook the role of the biophysical environment in our lives and how infections are often nurtured in animal hosts of which perhaps 40% possess the ability to spread to humans. Unfortunately, we have only identified around 1% of these viruses and remain largely ignorant of how they form an important part of animal life and they can spread to involve us.

We should also be aware that we are all infected by between 8 and 12 viruses without showing any symptoms.

For many years I have written much about how we live in an epidemic and pandemic age and how poorly prepared we are to handle such outbreaks. But many believe that we have nothing to worry about and that we can easily handle any infectious disease outbreak that confronts us.

If nothing else Coronavirus has forced us to reconsider such beliefs. But what apart from our ignorance is encouraging the emergence of infectious disease outbreaks?

Well, like it or lump it, climate change plays an important part in changing the distribution and range of animals and insects such as mosquitoes and ticks which harbour a number of infections. Extreme weather events, such as floods and droughts play a major role in this.

Dengue, a disease which has been a significant issue in Australia for the last 140 years is a good example. Changing patterns of rainfall encourages new breeding grounds for the mosquitoes which carry the infective agent.

But it is perhaps our behaviour which plays an important role in the emergence and spread of infectious diseases.