Pandemics – disorders that impact on a global scale – might seem like a thing of the past, but every year the World Health Organization (WHO) gathers to discuss strategies to combat them. This year, it added a new entry to its list of potential killer diseases – one unlike any other it has warned us about before.
The WHO publishes its list on an annual basis. It features diseases that the organization thinks need extra research and development funding. Criteria for inclusion range from a lack of vaccines or drugs that could be used to stop the spread of any given disorder, to its overall potential to cause widespread harm.
The list includes plenty of names with which you’re likely to be familiar, and that have caused headlines and panic around the world. One such example is the Ebola virus, which over a three-year span killed more than 11,000 people.
The WHO put the total number of suspected cases of Ebola during the west African outbreak at 28,616, meaning that more than 35 percent of those who contracted the virus were killed by it. And the malady wasn’t just confined to Africa, with reports of sufferers in the United States, the United Kingdom and Italy to mention just three, although the loss of life in those countries was minimal.
Perhaps most terrifyingly, the WHO believes that the numbers of official recorded cases of Ebola during the outbreak could well have been an underestimation. A study published in 2014 suggested that anywhere between 17 and 70 percent of cases in Africa could have gone unreported.
Another infamous virus on the WHO’s list is Zika. Between 2015 and 2016, an outbreak of the virus in Brazil rapidly spread to various countries across the globe. While it might not have the high fatality rate of Ebola, Zika can cause head and brain development problems for unborn babies. Normally spread by infected mosquitoes, the disease can also be passed between humans.
From the start of 2015 to the end of 2016, more than 40 countries around the world reported cases of the Zika virus. What started off in Brazil spread across South America, into Central and North America, and as far afield as the west Pacific and Africa. Travel bans and guidance was issued around the world as countries tried to stop the disease from reaching their shores.
While some cases came from mosquito bites, other countries were finding the Zika virus was being brought in by travellers moving to or coming home from areas that had been affected by the epidemic. While the disease might not be fatal in adults, it can cause a great deal of harm to unborn children. And currently there’s no known cure.
And some of the other viruses the WHO is concentrating on might not have had the publicity of Zika and Ebola, but are every bit as dangerous. Still. there’s a very real chance that the entry on the list known as Disease X might just trump them all, and it’s all down to one incredibly strange fact.
While the other diseases on the WHO list are very real, Disease X doesn’t actually exist. Or, to be more accurate, it refers to any problem that we currently know nothing about. To quote the WHO directly, “Disease X represents the knowledge that a serious international epidemic could be caused by a pathogen currently unknown to cause human disease.”
But what does that mean in practice? John-Arne Rottingen gives scientific advice to the WHO, and is the Norway Research Council’s chief executive. Speaking to The Telegraph newspaper in March 2018, he explained the reasoning behind including Disease X, “History tells us that it is likely the next big outbreak will be something we have not seen before.”
There are a number of potential sources for this new disease, but many of them stem from the same origin. According to some experts there’s a fair chance that the next worldwide epidemic could well be man-made. And the reasons for this range from the unintended to the horrifying.
One possible way Disease X could come about is via gene editing. The technology that allows scientists to play around with the genetic material of viruses could have terrifying consequences. It might sound like the plot of a dystopian sci-fi novel, but an error or a malicious act could release a modified virus into the population at large, with catastrophic results.
According to Rottingen, the potential for such a human-influenced outbreak is very real. “Synthetic biology allows for the creation of deadly new viruses,” he told the Telegraph. But that’s not the worst part of the equation, he said. “It is also the case that where you have a new disease there is no resistance in the population and that means it can spread fast.”
While that might be a scary thought, the likelihood of Disease X stemming from humans toying with genes is relatively slim. But that doesn’t make any potential outbreak any less worrying. And there’s scientific precedent to suggest that if Disease X did occur in a more natural way, the results could still be just as catastrophic in terms of the loss of human life.
The second, far more likely candidate for Disease X would be what’s known as a zoonotic disorder. These are diseases that make the jump from animals to humans, and the results of such leaps in the past have led to some of the worst outbreaks of health problems that the world has ever seen. And what makes this a more likely hazard stems from the way we interact with our environment.
Rottingen told the Telegraph that,“As the ecosystem and human habitats change, there is always the risk of disease jumping from animals to humans. It’s a natural process and it is vital that we are aware and prepare. It is probably the greatest risk.” And there are awful examples of the leap from animals to humans happening in the past.
Perhaps the worst example of a zoonotic infection is HIV. While no one can be certain, it’s believed that HIV was transmitted from infected chimpanzees being hunted for bushmeat. Since the early part of the 1980s, more than 35 million people have died because of HIV, according to the WHO. Ebola is a zoonotic disease as well.
Rottingen isn’t the only scientist who’s concerned. Professor Marion Koopmans is Head of Virosciences at Rotterdam’s Erasmus Medical Center. “The intensity of animal and human contact is becoming much greater as the world develops,” she told The Telegraph. “This makes it more likely new diseases will emerge, but also modern travel and trade make it much more likely they will spread.”
Wherever Disease X comes from, the WHO’s warning is that we need to be ready. So-called “plug-and-play platforms” need to be in place according to Rottinger, so scientists and doctors can react fast. Because according to journalist David Quammen in his book Spillover: Animal Infections and the Next Human Pandemic, “If you’re a thriving population, living at high density but exposed to new bugs, it’s just a matter of time.”