We live in an interconnected world: more people live in cities than at any time in human history, and they live closer to each other than ever before. As this new decade starts, travel between cities is quicker and cheaper than ever: more than half the world’s population live less than an hour from a major city; flight networks mean that almost every city in Africa, Asia and Europe is less than 18 hours apart—including with flight transfers.
This produces all sorts of wonders—from fashions to food, from Instagram experiences to cheaper prices. But exchange is not just about commerce or even the spread of ideas. Contact brings unforeseen and unexpected consequences, too. Disease is perhaps the most important—and is potentially catastrophic.
The “kill rates” of infectious diseases can be devastating, but sometimes this encourages us to look away. Although outbreaks of Ebola have been regular, the fact that the virus kills its hosts so quickly means that its spread can be prevented through exclusion zones and isolating populations that have or might have been exposed.
Plague can wreak more carnage, as it can incubate and spread more effectively: in the 1340s a change in climatic conditions contributed to the spread of plague, likely originating in Central Asia, spreading across the Middle East and Europe, where it killed perhaps as much as half the population. Highly contagious, the plague bacteria yersinia pestis is not only spread by fleas on rats (as we were taught at school) but can be transmitted by a variety of hosts—and can also spread in pneumonic form via respiratory droplets released through coughing. Like Ebola, plague still strikes regularly—there have been several outbreaks in China in 2019—but is containable as long as quarantine cordons are imposed quickly.
The real concern comes from pathogens that spread before action can be taken. According to the World Health Organisation (WHO), approximately one billion people contract seasonal influenza each year, resulting in between 290,000-650,000 deaths. That is bad enough. But far bigger dangers lurk when new strains appear. Particularly hazardous are strains that jump the species barrier—typically from birds or swine, creatures that are mixing vessels for influenza surface proteins to which humans are immunologically naive.
There have been several close shaves in recent years of avian and swine flu infections, which have threatened to spread across borders with devastating effect. Intensive poultry and pig-farming methods further heighten the risks: in 2019, a hundred million pigs in China died from swine flu, or were culled.
In 1918, an outbreak of avian influenza known as the “Spanish flu” infected a third of the world’s population. In the months that followed, an estimated 50m died—many more than had just been killed in the First World War. Deaths were exacerbated by high levels of pollution: poor air quality meant that respiratory illness proved deadly, not only with infants and the elderly, but also among healthy adults aged between 20 and 40.
The threat of something similar happening in the world of today and tomorrow is very real. What make the dangers far worse is the lack of a comprehensive global response plan to this—or to another epidemic or pandemic, perhaps created inadvertently or maliciously by new biotechnologies. Add in climate change and elevated pollution levels in much of Asia, and it is possible to conceive of death rates running into the tens if not hundreds of millions.
A survey produced in late 2019 by the Johns Hopkins Centre for Health Security and the Nuclear Threat Initiative revealed “severe weaknesses” in the ability of countries to prevent, detect and respond. Co-ordination both within and between countries—including wealthy states—leaves a great deal to be desired. The big practical challenge involves developing responses at national and international level that can co-ordinate and act in the face of a global pandemic, and also setting up a high-level response unit to “high-consequence biological events” that has access to significant resources—and is able to make difficult decisions about infected populations in one or multiple countries.
Fixing the problem is more about thinking things through than finance: the WHO estimates that the cost of planning for a pandemic is around $1 per person per year—or less than 1 per cent of the cost estimate of actually responding to a large-scale outbreak. Putting in place a co-ordinated, collaborative plan is not just important but essential.