by Bryan Walsh
Yet despite epidemic after epidemic, despite mass killers like smallpox and the 1918 flu, at no point has disease threatened humans with extinction. Even the Black Death, likely the most concentrated epidemic of all time, now appears as little more than a minor downturn in what has otherwise been a bull market for long-term human population growth. That’s true for animals as well. The International Union for Conservation of Nature reports that of the 833 plant and animal extinctions that have been documented since 1500, less than 4 percent can be attributed to infectious disease. Those species that were eradicated by disease tended to be small in number and geographically isolated—very much unlike human beings, who are both numerous and have spread to every corner of the world.38
With the exception of HIV—which can now be managed as a chronic condition with antiviral drugs—every major epidemic mentioned above took place before the dawn of modern medicine, before the development of antibiotics and widespread vaccines. Smallpox was even fully eradicated from the wild in 198039—the only known samples of the virus are kept at highly secure government facilities in Atlanta and Koltsovo, Russia.40 Plague is now so rare that when it breaks out in countries like Madagascar, it makes global news—yet fewer than 600 deaths from the disease were reported between 2010 and 2015. Studies have shown that most of the fatalities from the 1918 flu were actually due to secondary bacterial infections that today could be controlled by antibiotics,41 which were introduced less than a century ago. Influenza pandemics remain the great fear of infectious disease experts, but the most recent one in 2009 killed only about 284,000 people worldwide.42 That was fewer than the number of people who die from seasonal flu in an ordinary year.43
Modern science has defanged most infectious diseases, at least outside the developing world—and great progress has been made there in recent years—but basic evolution also plays a role in limiting the catastrophic potential of natural disease. Every pathogen faces a trade-off. In general, the more rapidly it kills, the harder it is to spread widely, because an extremely virulent disease would run out of victims and hit an epidemiological dead end. Pathogens that are highly transmissible, like influenza, rarely kill, even absent the countermeasures of modern medicine. The 1918 flu had a fatality rate of about 2.5 percent.44 That’s tremendously high by the standards of the flu, but it still meant that more than 97 out of every 100 patients survived. Even a virus like HIV—which kills slowly and shows no symptoms for years, permitting the infected plenty of time to spread the disease—is hindered because transmission requires direct contact with blood or with bodily fluids. The self-replication that makes infectious disease such an effective weapon also prevents it from becoming a true existential threat. What viruses and bacteria want—if packets of genes and single-celled organisms can be said to want anything—is to survive and to replicate. They can’t do that if they kill all humans.
The Nobel Prize–winning virologist Sir Frank Macfarlane Burnet could be forgiven for noting in 1962 that “to write about infectious disease is almost to write of something that has passed into history.”45 Sickness is with us always, and likely always will be. Infectious disease lives with us intimately, in the way a hypothetical supereruption or asteroid strike or nuclear bomb can’t. But even now in rich countries we’re far more likely to die of noncommunicable diseases like heart attacks or cancer or Alzheimer’s, rather than from the pathogens that reaped our ancestors. The decline of infectious disease is the best evidence that life on this planet truly is getting better.
Yet there is no guarantee these trends will continue. The number of new infectious diseases like SARS and HIV has increased by nearly fourfold over the past century,46 while since 1980 alone the number of outbreaks per year has more than tripled.47 Over the past fifty years we’ve more than doubled the number of people on the planet,48 which means more human beings to get infected and in turn to infect others, especially in densely populated cities. We have more livestock now than in the last ten thousand years of domestication to 1960 combined.49 As SARS demonstrated, our interconnected global economy, with its long supply chains, is uniquely vulnerable to the global disruption that can be wrought by infectious diseases, even those that kill in relatively small numbers. That same interconnection—the ability to get to nearly any spot in the world in twenty hours or less, and pack a virus along with our carry-on luggage—allows new diseases to emerge that might have died out in the past. Antibiotics have saved hundreds of millions of lives since the serendipitous discovery of penicillin in 1928, but bacterial resistance to these drugs is growing by the year, a development doctors believe is one of the greatest threats to global public health. Thirty-three thousand people die each year from antibiotic-resistant infections in Europe alone, according to a 2018 study.50 The “antibiotic apocalypse,” as England’s chief medical officer, Sally Davies, called it,51 puts us in danger of returning to a time when even run-of-the-mill infections could kill.
For all the advances we’ve made against infectious disease, our very growth has made us more vulnerable, not less, to microbes that evolve 40 million times faster than humans do.52 A World Bank study estimated that a severe influenza pandemic along the lines of the 1918 flu could cost our now much richer and more connected global economy $4 trillion, nearly the entire GDP of Japan,53 and some experts believe it could kill hundreds of millions of people.54 The WHO, which performed so well under the stress of SARS, has botched more recent outbreaks so badly that experts have called for the entire organization to be overhauled. Climate change is expanding the range of disease-carrying animals and insects like the Aedes aegypti mosquitoes that transmit the Zika virus. Even human psychology is at fault—the spread of vaccine skepticism has been accompanied by the resurrection of long-conquered diseases like measles, leading the WHO in 2019 to name the antivaccination movement as one of the world’s top ten public-health threats.55
Dr. Peter Piot is the director of the London School of Hygiene & Tropical Medicine and the man who in 1976 helped discover the Ebola virus. He and his team traveled from village to remote village in what is now the Democratic Republic of the Congo, tracking the first known outbreak of Ebola at great personal risk. He has witnessed firsthand the worst that biology can throw at us—and he is worried about what’s to come. “We face the globalization of risk in infectious disease today,” Piot told me in 2017. “In the future that risk will only go up. That is a fact of life.”
And the best way to understand that fact is to revisit what happened—and what was only narrowly prevented—when Ebola broke out in the globalized world of 2014.
Scientists thought they knew Ebola. Like SARS, the virus probably has its reservoir in bats—though researchers have yet to pinpoint the exact origin species—but it would occasionally jump to infect human beings in isolated rural communities in central Africa. When it did so it would kill, and terribly—burning fevers, shortness of breath, vomiting, diarrhea, and even external bleeding, sometimes from the whites of the eyes. But Ebola would kill so quickly, and in such remote territory, that outbreaks would soon burn through available victims. International medical teams in their hazmat suits would show up to contain the virus. Ebola was the stuff of medical nightmares, less a virus than a real-life bogeyman used for scare stories like the 1995 film Outbreak. But was it a global health threat? No.
That began to change in December 2013, when a two-year-old boy in the village of Meliandou in the West African nation of Guinea became ill with Ebola. The location was the first surprise—Guinea is as far away from Ebola’s usual turf in Central Africa as Las Vegas is from New York City. The next surprise came when the disease kept spreading through West Africa, breaking out of the villages where Ebola was usually found and into the Guinean and Liberian capitals of Conakry and Monrovia, each home to more than one million people. Ebola in a city, with countless human bodies to feast on—this was the sum of all fears. And as the months passed in 2014, this is what was happening.
Tracing the origin of the outbreak months l
ater, scientists wondered if the Ebola virus had changed, if it had mutated to become more transmissible. But it wasn’t the virus that had changed so much—it was Africa. Development and infrastructure improvement, including thousands of miles of road built by Chinese investment,56 had cleared the thick forests that had once kept both the virus and its victims isolated. Deforestation flushed out the animals that carried Ebola, making contact with humans—and the chance of a new Ebola infection, like the one that sickened that first boy in Meliandou—all the more likely. (One study found that deforestation is linked to 31 percent of outbreaks such as Ebola and Zika.57) The roads built to carry trucks and logging crews also made it easier for rural villagers to move to Africa’s growing cities, bringing the emerging pathogens of the wild with them.
I saw this for myself on a reporting trip to Cameroon in Central Africa in July 2011. Those who live in this region, like other rural parts of Africa, have long depended on hunting the occasional wild animal—porcupines, cat-sized antelopes called dik-diks, even monkeys—to supplement their diets with protein. The product of those hunts are called bush meat, and the appetite for it has increased as even the poorest Africans have grown richer and new roads allow hunters to penetrate deeper into the forest. Driving away from the Cameroonian capital of Yaoundé one hot July day, I counted stand after roadside stand, each selling fresh bush meat.
The act of hunting and slaughtering a live animal is a bloody one, for both predator and prey, and viruses can easily pass between them. In one small settlement I listened as a Cameroonian health official warned villagers about the health dangers posed by bush meat. Then I walked into a hut where a woman and her son were butchering a fresh porcupine. They skinned the animal, then boiled it to strip off the quills. Once the flesh was pink and raw, the woman began tearing into its belly with a machete, pulling out the yellow, glistening viscera. Blood began to flow as she quartered the quivering carcass, kneading the meat with her hands. This was an encounter with another species more microbiologically intimate than sex, with all the attendant medical risks.58 Multiply that interaction a thousandfold each day—any of which could permit a dangerous virus to jump from animals to humans—and it becomes clear that a major Ebola outbreak was inevitable.
By the end of July 2014, the virus had established itself in the capital cities of Guinea, Liberia, and Sierra Leone. More than 1,200 people had fallen ill, making this by far the biggest Ebola outbreak on record. There was no treatment for Ebola beyond supportive care focused on maintaining hydration and oxygen levels. Doctors tried their best to isolate sick patients, preventing them from spreading the disease, until the outbreak could be contained. But that strategy works only in the kind of sparsely populated territories where Ebola had previously struck. It was impossible to control the outbreak in cities using the same tactics. There weren’t enough isolation units, not enough doctors or nurses. Local medical staff were often the first to get sick, even as they found themselves ostracized by their communities for working with Ebola patients. Cultural practices threw unexpected curveballs—it was months into the outbreak before researchers realized that traditional burial habits, including the practice of family members washing the bodies of the deceased, gave the virus access to a buffet of potential hosts.59 None of this was foreseen, and the result was a health catastrophe that eventually took the lives of more than ten thousand people. And it came so close to being much, much worse.
Dr. Tom Frieden was the director of the Centers for Disease Control and Prevention (CDC) under President Barack Obama for 2,783 days60—and the one that scared him the most came on July 23, 2014.61 That was the day Frieden received the news that a man had died of Ebola in the Nigerian megacity of Lagos. As alarming as the outbreak had been up until then, this case represented a threat of an entirely different magnitude. Lagos is the biggest city in Africa, with a population around the same size as those of Guinea, Liberia, and Sierra Leone combined. While those nations were relatively isolated from the rest of the world, Lagos is a major international air travel hub. “That was the moment of maximum terror,” Frieden told me. “If it got completely out of control in Lagos, it could spread through Nigeria and the rest of Africa. It could have continued for months to years. It could still be going on.”
The Nigerian government’s initial response was sluggish, but things changed when Frieden dispatched CDC staff to Lagos to work alongside a cadre of Nigerians with experience in the international campaign to eradicate polio. Health officials traced hundreds of possible Ebola contacts and were able to confirm and isolate nineteen further cases62 connected to the original death. They halted the chain of infection, preventing Ebola from gaining a foothold in Africa’s most populous country. But today all Frieden can think about is how lucky we were—and how we may not always be so fortunate. “We were not more than a couple of days away from Ebola not being readily controlled,” he said. “That shows how close we are to a possible disaster.”
Even so, Frieden and the CDC couldn’t prevent Ebola from reaching the United States. In mid-September, a Liberian named Thomas Eric Duncan contracted the disease in his home country before flying to Dallas to visit family. He would die in October at Texas Health Presbyterian Hospital, but not before infecting two nurses, Nina Pham and Amber Vinson. It was the first time Ebola had spread on American soil, and Pham and Vinson were both put in specially prepared isolation wards.
The homegrown cases made Ebola suddenly real to Americans, sparking a public panic that was further sensationalized by too many in the media. I had a close encounter with the hysteria myself. One night that month I appeared on MSNBC’s The Last Word with Lawrence O’Donnell for what was supposed to be a short segment to discuss Time’s Ebola coverage, only for the show to pivot and spend an hour watching Pham’s ambulance move in real time from an airplane to a government hospital in Bethesda, Maryland, mile by slow mile. All the while I kept searching for something, anything interesting to say on live TV about a situation none of us fully understood. It was like one of those nightmares where you show up for an exam without your pants.
Fortunately Pham and Vinson both recovered, and the domestic Ebola outbreak ended with them, save for a few isolated cases imported from Africa. But had it continued, would even our $2.9 trillion U.S. health care system63 have been sufficient to prevent a potential wipeout?
At the start of the Ebola outbreak there were only three biocontainment units in the United States that could treat patients such as Pham and Vinson: the University of Nebraska Medical Center, the National Institutes of Health in Bethesda, and Emory University Hospital in Atlanta. As of 2018 there are now fifty such facilities across the United States, but that still adds up to only 144 beds.64 To respond to just ten cases of Ebola in 2014, the American government spent $119 million on screening and quarantine alone. In an outbreak of any greater size—say, of a new disease that is more contagious than Ebola—that kind of response would not scale.
Those new biocontainment facilities were paid for with the billions of dollars Congress allocated to disease response in the wake of the Ebola outbreak. But that funding ends in 2020, which means financial support could fall off a cliff. The budget of the Public Health Emergency Preparedness Program, which helps state and local health departments surveil for infectious disease and train epidemiologists, has dropped by more than a third from its $940 million peak in 2002. Local health departments have cut more than 55,000 jobs. These are the frontline workers in any epidemic; laying them off in mass numbers is like firing your infantry before an invasion. The CDC’s Global Health Security Agenda—an international program that works to foil diseases overseas before they reach the United States, just as the CDC did with Ebola in Nigeria—is being downsized dramatically, and in 2018 the CDC announced that its work in 39 out of 49 countries would be scaled back or shut down completely.65 In May 2018, the head of global health security at the White House’s National Security Council abruptly resigned after his office was essentially eliminated.66
Donald Trump does not inspire the same degree of confidence. During the 2014 Ebola outbreak—before he became a candidate for president—he called for preventing American health care workers who had been infected with the virus from returning to the country.68 He warned without evidence on Twitter that “Ebola is much easier to transmit than the CDC and government representatives are admitting.”69 As president, Trump oversees a government that has been hollowed out of health expertise. His first CDC director, Dr. Brenda Fitzgerald, was forced to resign over her investments in tobacco,70 while his first HHS secretary, Dr. Tom Price, had to resign over taking charter flights at taxpayer expense.71 It was more than a year and a half into his term before Trump finally appointed a White House science adviser. Obama’s first secretary of energy was Dr. Steven Chu, who is a Nobel Prize–winning physicist. Trump’s secretary of energy is former Texas governor Rick Perry, who wears glasses.
