Roughly 7.3 billion people inhabit the Earth, and that figure is expected to balloon to nearly 10 billion by 2050, according to United Nations estimates. All those people need places to live and food to eat. And that means recent global rises in urbanization, population migration, and the conversion of natural habitats to agricultural land are all likely to continue — and probably accelerate.
From the perspective of virologists and other people who study human disease, those are scary trends.
“The potential for new pathogens to emerge is great,” says Amanda McClelland, a senior vice president of the “prevent epidemics” team at the non-profit Resolve to Save Lives. McClelland says urbanization and climate change are almost-certain drivers of novel diseases or the reemergence of infections that were once well-contained. And there’s only so much she and other public health officials can do to foresee and contain outbreaks. “There’s a lot of work going on in terms of predicting where these could come from, but one thing we know is that viruses continue to surprise us,” she says. “Our models tell us where to look, but I’m sure there’ll be something we can’t prepare for.”
Other experts share her concerns.
Add in global changes to the ways people live and commingle, and many new health concerns are on the horizon.
“Habitat destruction and the loss of biodiversity can favor the types of species often responsible for infectious disease outbreaks,” says Richard Ostfeld, PhD, a distinguished senior scientist at the Carey Institute of Ecosystem Studies. Ostfeld explains that converting wild lands into food-producing ones and “chopping forests into little bits” scare away large predators and allow small animals — mice, rats, and other foragers — to thrive. “These are the species that tend to harbor dangerous pathogens,” he says.
Add in global changes to the ways people live and commingle, and many new health concerns are on the horizon. Here are eight that could emerge in the very near future.
Antibiotic Resistant E-Coli
For decades, experts have been warning about the emergence of antibiotic-resistant bacteria. “The problem is the massive overuse and abuse of antibiotics in animal production and human medicine,” says Lance Price, PhD, a professor and founding director of the Antibiotic Resistance Action Center at George Washington University’s Milken Institute School of Public Health. “We know the more we use antibiotics, the more resistant bacteria will emerge.”
Price says lawmakers and regulators have been slow to implement safeguards — either for economic reasons or because it was presumed some new antibiotic drug would be developed. He says this is folly. “There are probably not an infinite number of compounds that can specifically kill bacteria and not kill us, but even if there were, drug companies are getting out of the business of developing antibiotics because there’s much more money to be made making drugs people take every day for a lifetime, not on drugs you take every few years for three to 10 days,” he says.
It’s not a question of whether new antibiotic-resistant bacteria will emerge. They’re already here. “Twenty-three thousand people died last year of untreatable infections,” Price says. “When we get new bacteria that are resistant to all our antibiotics, that number’s going to shoot way up.” He mentions E. coli and Staphylococcus as two types of infectious bacteria that could make the jump. “I don’t think we’re going to see bacteria that wipe out civilization,” he adds. “But before antibiotics, a lot of people used to die young from minor infections.”
Asian Longhorn Tick Disease
As climate change and land development continue to increase the geographic range and population density of ticks, Ostfeld says it’s likely that new tick-borne diseases will emerge — to say nothing of the explosion in Lyme disease cases in recent years. He points out that the Asian longhorn tick was recently discovered in New Jersey, and that — at least in Asia — this tick carries and transmits a deadly viral pathogen. “We don’t know how it got here, but we know now it has been here for years,” he says.
While the deadly pathogen it carries hasn’t yet turned up in North American populations, Ostfeld says he’d be “surprised” if it didn’t emerge soon. Even if it doesn’t, he says, ticks harbor pathogens that evade expert scrutiny — many of which can emerge suddenly or combine with others to form new or deadly diseases. “We have a powder keg out there,” he says of ticks. “There’s plenty of dry fuel, so new pathogens are going to erupt.”
Ancient Viruses from Arctic Permafrost
The Earth’s melting polar ice caps get a lot of attention, but most of the focus is on rising sea levels. That could change in a hurry if a long-lost virus — something locked for millennia in the arctic permafrost — reemerges. Researchers have already turned up the DNA of a 30,000-year old “giant” virus in the Siberian ice. “Special environments such as deep ocean sediments and permafrost are very good preservers of microbes and viruses because they are cold, anoxic, and in the dark,” explains Chantal Abergel, PhD, director of research at France’s Structural and Genomic Information Laboratory and coauthor of that Siberia study.
The pertinent questions are where and when this will happen, and how horrific the fallout will be.
While the giant virus Abergel and her colleagues found doesn’t seem to be a threat to people, she says her findings are evidence that microbes with the potential to cause “planet-wide epidemics” could be preserved in ancient layers of arctic ice. “Each year, the superficial permafrost layers are melting and releasing buried microorganisms,” and this process is steadily accelerating, Abergel says. Mining and drilling operations are also bringing people into contact with these melting permafrost regions. “This is a good recipe for disaster,” she warns.
V.R. Gaming Addiction
There’s often a fine line between recreation and addiction. But since 2013, when the American Psychiatric Association deemed “internet gaming disorder” a condition warranting increased scrutiny, more and more researchers have been sounding the alarm about the negative consequences of gaming addiction — especially among men.
A recent review study from the University of British Columbia found that, contrary to some popular misconceptions, the majority of gamers are over 18. The study also found that gaming has all the hallmarks of addiction — including increased tolerance, cravings, and withdrawal — and that it’s accompanied by negative consequences (like the loss of a job or relationships) associated with other harmful addictive substances. Research has also linked heavy gaming to mental health disorders, including anxiety and depression. There’s widespread speculation that, as virtual reality (V.R.) technology makes these games even more immersive and “real,” gaming addiction and its attendant harms will skyrocket.
A New Mosquito-Borne Virus
“As medical entomologists dealing with vector-borne pathogens, the emergence of a novel pathogen is a scenario we really worry about,” says Jonathan Day, PhD, a professor of medical entomology at the University of Florida. He talks about climate change and shifting weather patterns — warm fronts and excessive rain in places that used to be mild and relatively arid — and how these factors could lead to mosquitos migrating to new areas. “Anything that changes the habitat where a mosquito lives could lead it to feed off new hosts,” he says, meaning people, but also wild and domestic animals.
Different hosts carry different viruses, and these can intermingle inside a mosquito and generate novel pathogens. “Those sorts of recombinant viruses come out of nowhere and have the potential to be highly contagious, like Ebola,” he explains. “And the types of viruses that have the potential of combining — we don’t even know all of them.” It’s not a matter of if one of these new viruses will emerge. They will, Day says. The pertinent questions are where and when this will happen, and how horrific the fallout will be.
Diseases Tied to Nanoparticle-Induced Immune System Toxicity
Nanoparticles are almost infinitesimally small biological and synthetic objects, and they’re now being used in everything from pharmaceutical drugs to food dyes. While nanoparticles now play a life-saving role in some forms of medical testing and treatment, research suggests they can also have “immunotoxic” effects — altering human immune function in unpredictable (and largely unstudied) ways. “Nanoparticles can interact with various components of the immune system and either enhance or inhibit its function,” according to a 2014 study from Texas A&M University.
More research indicates that nanoparticles have the ability to induce inflammation and that they can cross cell barriers and cause DNA damage within “privileged sites” in the body. One study has even tied nanoparticles used in food additives to heightened symptoms among people with inflammatory bowel disease. It’s possible that the widespread use of nanoparticles and the resulting human exposures could produce new inflammatory conditions or heighten rates or symptoms of existing ones, from Crohn’s disease to arthritis and diabetes.
The psychological term “dysphoria” refers to a general state of unease, anxiousness, or dissatisfaction with life. There’s currently a good deal of expert speculation that, for some, heavy use of personal and mobile technologies (namely smartphones) is producing disorientation or anxiety. And the incorporation of more powerful and more invasive technologies may exacerbate some of these effects.
“The challenge with all these new technologies is that they’re disrupting the ways we think and communicate, and we don’t know the long-term effects of that,” says Gary Small, MD, a professor of psychiatry and biobehavioral sciences at the David Geffen School of Medicine at UCLA. He points to the “staccato” quality of online interaction and communication — the drive to jump from task to task or site to site, never pausing to consider or extract deep meaning.
And the incorporation of more powerful and more invasive technologies may exacerbate some of these effects.
New, Uncontained Types of Influenza
Between 1918 and 1919, a form of the H1N1 flu subtype killed as many as 100 million people worldwide. That type of devastation is still possible today and may come about for the most frustrating of reasons. “A large part of our job now is rumor management — or trying to counteract false or misleading rumors with real information,” McClelland says.
She explains that, during the early stages of an outbreak, containment is often possible if affected communities and public health officials can stay on the same page. But more and more, that sort of coordination is thwarted by misinformation and a lack of faith. “The breakdown in trust between populations and governments and the media has become a massive issue for us,” she says. “In West Africa, we’ve already seen conspiracies that scientists created an outbreak, or that it wasn’t real, or there were rumors about side effects of the vaccines that weren’t true.”
Misinformation often travels faster than legitimate information, she adds, “and at the moment we’re seeing this big breakdown in trust not just in communities with low health literacy, but in countries where internet rumors and conspiracy theories spread really quickly.” It’s possible that, as a result of public mistrust and internet-propagated rumors, a new and deadly form of influenza will emerge and outpace containment efforts.