Australia's Chief Scientist

Epidemics: expecting the unexpected

Dealing with epidemics can be a complicated and devastating task – the recent cholera outbreaks in Haiti and Papua New Guinea  are just one example of health workers pushed to their limits in an attempt to contain the disease.

Although well known diseases with existing treatments, like cholera, can erupt into epidemics, recent years have also seen global outbreaks of new pathogens including sudden acute respiratory syndrome (SARS) and the H1N1 influenza (swine flu).

In these instances, the digital age of instantaneous communication played a significant role in the rapid and effective response to these outbreaks.Scientists across the world were able to share results almost instantly, creating a global digital laboratory. The causative pathogens were rapidly identified and the progress of the spread of the diseases was closely monitored and necessary instructions for containment were almost instantly available around the world.

But there is a delicate balance between scientific advancement and our modern lifestyles when it comes to susceptibility to the spread of epidemics.

Last year, a report  tabled at the Prime Minister’s Science, Engineering and Innovation Council looked at factors affecting the spread of epidemic diseases and how Australia might prepare for future outbreaks.

The report stated that the rate of mass public, local and international travel means a group of individuals can be exposed to a disease and spread to all corners of the globe long before the first symptom is reported to a doctor, let alone before a new disease and its potential ramifications are identified or understood.

Modern high-density living and food production methods are also quite literally a breeding ground for new infectious diseases.

Furthermore, increased desire for meat based diets means that humans are in closer contact with species such as pigs and birds which can be a source of potential pathogens. Higher density animal husbandry also means that multiple species can be in close contact in large numbers facilitating the transmission of diseases, in turn providing greater opportunity for mutation and the emergence of new and potentially more infectious strains.

All these factors mean that there is increased likelihood of serious epidemics to occur. The cause, geographic origin, severity, impact and other factors cannot be predicted.

Epidemics are not a modern phenomenon and have the potential to escalate. The Spanish Influenza pandemic which began in 1918 quickly swept the globe and resulted in more deaths in a shorter time than the World War which preceded it. It was a devastating pandemic at a time when viruses and how best to treat them were not yet well understood scientifically or medically.

Spanish Influenza is just one example of the many deadly outbreaks of infectious disease to hit the human race in recent centuries. In fact, even diseases that we now vaccinate against were once huge killers world wide like measles, polio and smallpox.

Small pox was a devastating illness that not only caused significant numbers of deaths, but also left many survivors with serious complications including disfiguring scarring and blindness.

It also represents a serious battle and one of the first major triumphs of science over an ancient disease which decimated populations and changed the course of human history.

Early observations showed that those who survived the disease were not susceptible to further infection. As a result, initial preventative treatment methods included inoculation – applying material from the sores of people with active illness under the skin of healthy individuals. This method usually resulted in a mild case of smallpox but one that still proved fatal in a number of cases, albeit it far less frequently than natural infection.

After a noticing a link between milkmaids who had been exposed to cowpox and immunity to smallpox, English scientist and country doctor, Edward Jenner, experimented with the use of cowpox as a vaccine. This was demonstrated, in what were arguably the world’s first clinical trial, to provide immunity without the risk of serious smallpox infection.

Even with vaccines, diseases with epidemic potential can be hard to eradicate Despite the fact that the breakthroughs in smallpox vaccination occurred in the 1700-1800s, it was not until 1980, after a global vaccination campaign, that the World Health Organisation was able to declare the world free of smallpox. This announcement was made by Australian scientist Professor Frank Fenner, who was chairman of the Global Commission for the Certification of Smallpox Eradication and played a key role in the investigations that proved the disease was gone.

To learn more about epidemics, or how Australia can prepare, you can download the report ‘Epidemics in a Changing World’ here.