Ebola: The Natural and Human History of a Deadly Virus

by David Quammen

  A pregnant woman, showing signs of hemorrhagic fever, delivered her baby and then died. The baby, left in the care of a grandmother, soon died too. That was sad but not peculiar; orphaned infants often die in the hard conditions of a village. More notable was that the grandmother also died. An ape (unidentified, but chimp or gorilla) reportedly bit a domestic goat, infecting it; the goat was slaughtered in due course, skinned by a thirteen-year-old boy, and then the boy’s family began falling ill. No, a dead monkey was eaten. No, bats were eaten. Mostly these tales couldn’t be substantiated, but their currency and their general themes reflected a widespread, intuitive comprehension of zoonoses: Relations between humans and other animals, wild or domestic, must somehow lie at the root of the disease troubles. In early December, and then again in January 2008, came reports of suspicious animal deaths (monkeys and pigs) in outlying regions of the country. One of those reports also involved dogs that died after being bitten by the sickened monkeys. Was it an epidemic of rabies? Was it Ebola? The Ministry of Health sent people to collect specimens and investigate.

  “Then there was a new epidemic—of fear,” said Dr. Sam Okware, Commissioner of Health Services, when I visited him in Kampala a month later. Among Dr. Okware’s other duties, he served as chairman of the national Ebola virus task force. “That was the most difficult to contain,” he said. “There was a new epidemic—of panic.”

  These are remote places, he explained. Villages, settlements, small towns surrounded by forest. The people feed themselves mostly on wildlife. During the Bundibugyo outbreak, residents of that area were shunned. Their economy froze. Outsiders wouldn’t accept their money, scared that it carried infection. Population drained from the major town. The bank closed. When patients recovered (if they were lucky enough to recover) and went home from the hospital, “again they were shunned. Their houses were burned.” Dr. Okware was a thin, middle-aged man with a trim mustache and long, gesticulant hands that moved through the air as he spoke of Uganda’s traumatic year. The Bundibugyo outbreak, he said, was “insidious” more than dramatic, smoldering ambiguously while health officials struggled to comprehend it. There were still five questions pending, he said, and he began to list them: (1) Why were only half of the members of each household affected? (2) Why were so few hospital workers affected, compared to other Ebola outbreaks? (3) Why did the disease strike so spottily within the Bundibugyo district, hitting some villages but not others? (4) Was the infection transmitted by sexual contact? After those four he paused, momentarily unable to recall his fifth pending question.

  “The reservoir?” I suggested. Yes, that’s it, he said: What’s the reservoir?

  Bundibugyo virus in Uganda, 2007, completes the outline sketch of ebolavirus classification as presently known. Four different ebolaviruses are scattered variously across sub-Saharan Africa and had emerged, as of that year, from their reservoir hosts to cause human disease (as well as gorilla and chimpanzee deaths) in six different countries: Sudan, Gabon, Uganda, Côte d’Ivoire, the Republic of the Congo, and the Democratic Republic of the Congo. (This was the state of distributional knowledge until the West Africa outbreak of 2014, which I’ll discuss in the epilogue, below.) A fifth ebolavirus seems to be endemic to the Philippines, and to have traveled from there several times to the United States in infected macaques. But how did it get to the Philippines, if the ancestral origin of ebolaviruses is equatorial Africa? Could it have arrived there in one soaring leap, leaving no traces in between? From southwestern Sudan to Manila is almost seven thousand miles as the bat flies. But no bat can fly that far without roosting. Are ebolaviruses more broadly distributed than we suspect? Should scientists start looking for them in India, Thailand, and Vietnam? (Antibodies for Ebola virus or something closely related seem to have been found among people in Madagascar. Go figure.) Or did Reston virus get to the Philippines the same way Taï Forest virus got to Switzerland and Ebola virus to Johannesburg—by airplane?

  If you contemplate all this from the perspective of biogeography (the study of which creatures live where on planet Earth) and phylogeny (the study of evolving lineages), one thing becomes evident: The current scientific understanding of ebolaviruses constitutes pinpricks of light against a dark background.

  8

  PEOPLE IN THE villages where Ebola struck—the survivors, the bereaved, the scared but lucky ones not directly affected—had their own ways of understanding this phenomenon, and one way was in terms of malevolent spirits. In a single word, which loosely encompasses the variety of beliefs and practices seen among different ethnic and language groups and is often used to explain rapid death of adults: sorcery.

  The village of Mékouka, on the upper Ivindo River in northeastern Gabon, offers an instance. Mékouka was one of the gold camps in which the outbreak of 1994 got its start. Three years later, a medical anthropologist named Barry Hewlett, an American, visited there to learn from the villagers themselves how they had thought about and responded to the outbreak. Many local people told him, using a term from their Bakola language, that this Ebola thing was ezanga, meaning some sort of vampirism or evil spirit. Asked to elaborate, one villager explained that ezanga are “bad human-like spirits that cause illness in people” as retribution for accumulating material goods and not sharing.7 (This wouldn’t seem to apply to that man on the upper Ivindo, in 1994, who shared his tainted gorilla meat before he died.) Ezanga could even be summoned and targeted at a victim, like casting a hex. Neighbors or acquaintances, envious of the wealth or power someone has amassed, could send ezanga to gnaw at the person’s internal organs, making him sick unto death. That’s why gold miners and timber-company employees suffered such high risk of Ebola, Hewlett was told. They were envied and they didn’t share.

  Barry Hewlett had investigated the Mékouka outbreak in retrospect, months after the events occurred. Still fascinated by the subject, and concerned that an important dimension was being omitted by the more clinical methods of research and response, he got himself to the scene in Gulu, Uganda, in late 2000, while that outbreak was still going on. He found that the predominant ethnic group there, the Acholi, were also inclined to attribute Ebola virus disease to supernatural forces. They believed in a form of malign spirit, called gemo, that sometimes swept in like the wind to cause waves of sickness and death. Ebola wasn’t their first gemo. The Acholi previously suffered epidemics of measles and smallpox, Hewlett learned, and those were likewise explained. Several elders told Hewlett that disrespect for the spirits of nature could bring on a gemo.

  Once a true gemo was recognized, as distinct from a lesser spate of illness in the community, Acholi cultural knowledge dictated a program of special behaviors, some of which were quite appropriate for controlling infectious disease, whether you believed it was caused by spirits or by a virus. These behaviors included quarantining each patient in a house apart from other houses; relying on a survivor of the epidemic (if there were any) to provide care to each patient; limiting movement of people between the affected village and others; abstaining from sexual relations; not eating rotten or smoked meat; and suspending the ordinary burial practices, which would involve an open casket and a final “love touch” of the deceased by each mourner, filing up for that purpose.8 Dancing was also prohibited. Such traditional Acholi strictures (along with intervention by the Uganda Ministry of Health and support from the CDC, Médecins sans Frontières, and the WHO) may have helped suppress the Gulu outbreak.

  “We have a lot to learn from these people,” Barry Hewlett told me, one day in Gabon, “as to how they’ve responded to these epidemics over time.” Modern society has lost that sort of ancient, painfully acquired accumulation of cultural knowledge, he said. Instead we depend on the disease scientists. Molecular biology and epidemiology are useful, but other traditions of knowledge are useful too. “Let’s listen to what people are saying here. Let’s find out what’s going on. They’ve been living with epidemics for a long time.”

  Hewlett is a gentle-spirited man with a
professorship at Washington State University and two decades of field experience in Central Africa. By the time I met him, at an international ebolavirus conference in Libreville, we had each visited one other village famed for suffering the disease—a place called Mbomo, in the Republic of the Congo, along the western edge of Odzala National Park. Mbomo lies not far from the Mambili River and the Moba Bai complex, where I had watched Billy Karesh trying to dart gorillas. The outbreak around Mbomo began in December 2002, probably among hunters who handled infected gorillas or duikers, and spread throughout an area that encompassed at least two other villages. A large difference between Hewlett’s experience in Mbomo and mine was that he arrived during the outbreak. The grease was still flaming in the pan when he made his inquiries.

  One early patient, Hewlett learned, was pulled out of the village clinic because his family disbelieved the Ebola diagnosis and preferred relying on a traditional healer. After that patient died at home, unattended by medical personnel and uncured by the healer, things got testy. The healer pronounced that this man had been poisoned by sorcery and that the perpetrator was his older brother, a successful man working in a nearby village. The older brother was a teacher who had “risen” to become a school inspector and didn’t share the good fortune with his family. So again, as with ezanga among the Bakola people in northeastern Gabon, there were jealous animosities underlying the accusations of sorcery. Then another brother died, and a nephew, at which point family members burned the older brother’s Mbomo house and sent a posse to kill him. They were stopped by the police. The older brother, though now taken for an evil magus, escaped vengeance. Then community relations deteriorated generally as more victims died from the invisible terror, with no cure available, no satisfactory explanation, to a point where anyone who looked out of the ordinary or above the crowd became suspect.

  Another element of the dangerous brew in and around Mbomo was a mystic secret society, La Rose Croix, more familiar (if barely) to you and me as Rosicrucianism. It’s an international organization that has existed for centuries, mostly devoted to esoteric study, but in this part of the Congo it had a bad reputation, akin to sorcery. Four teachers within one nearby village were members, or were thought to be members—and these teachers had been telling children about Ebola virus before the outbreak occurred. That led some traditional healers to suspect that the teachers had advance knowledge—supernatural knowledge—of the outbreak. Something had to be done, yes? On the day before Barry Hewlett and his wife arrived in Mbomo, the four teachers were murdered with machetes while they worked in their crop fields.

  Soon afterward, the disease outbreak expanded to include so many community members that sorcery no longer seemed a plausible explanation to local people. The alternative was opepe, an epidemic, Mbomo’s equivalent (in Kota, one of the local languages) to what Barry Hewlett had heard about, from the Acholi, as gemo. “This illness is killing everyone,” one local man told the Hewletts, and therefore it couldn’t be sorcery, which targets individual victims or their families.9 By early June 2003, there had been 143 cases in Mbomo and the surrounding area, with 128 deaths. That’s a case fatality rate of 90 percent, at the top of the range even for Ebola virus.

  With their deep interest in local explanations and their patient listening methods, the Hewletts heard things that wouldn’t fit within the multiple-choice categories of an epidemiological questionnaire. Another of their informants, an Mbomo woman, declared: “Sorcery does not kill without reason, does not kill everybody, and does not kill gorillas or other animals.”10 Oh, yes, again gorillas. That was another aspect of the Mbomo brew—everyone knew there were dead apes in the forest all roundabout. They had died at the Lossi sanctuary. They had died, so far as Billy Karesh could tell, at Moba Bai. Carcasses had been seen in the environs of Mbomo itself. And, as the woman said, sorcery didn’t apply to gorillas.

  9

  WHEN A SILVERBACK gorilla dies of Ebola, he does it beyond the eyes of science and medicine. No one is there in the forest to observe the course of his agony, with the possible exception of other gorillas. No one takes his temperature or peers down his throat. When a female gorilla succumbs to Ebola, no one measures the rate of her breathing or checks for a telltale rash. Thousands of gorillas may have been killed by the virus but no human has ever attended one of those deaths—not even Billy Karesh, not even Alain Ondzie. A small number of carcasses have been found, some of which have tested positive for Ebola antibodies. A larger number of carcasses have been seen and reported by casual witnesses, in Ebola territory at Ebola times, but because the forest is a hungry place, most of those carcasses could never be inspected and sampled by scientific researchers. The rest of what we know about Ebola’s effect on gorillas is inferential: Many of them—major portions of some regional populations, such as the ones at Lossi, Odzala, and Minkébé—have disappeared. But nobody knows just how Ebola virus affects the gorilla body.

  With humans it’s different. The numbers I’ve mentioned above offer one gauge of that difference: 245 fatal cases during the outbreak at Kikwit, another 224 at Gulu, 128 in and around Mbomo, et cetera. The total of known human fatalities from ebolavirus infection, from the discovery of the first ebolaviruses in 1976 through the end of 2012, was about 1,580. The West African outbreak of 2014 (which seems to have begun in southern Guinea, as early as December 2013) has more than doubled the total as of this writing, with no end yet in sight; the death count is rising so quickly, right now, that it’s pointless for me to print a number. Although the suffering has been awful, the total is still relatively low compared to the tolls taken by such widespread and relentless global afflictions as malaria and tuberculosis, or to the great waves of death brought by the various influenzas. But it’s high enough to have yielded a significant body of data. Furthermore, doctors and nurses have seen many of those victims die. So the medical profession knows a good bit about the range of symptoms and the pathological effects produced on a human body during death by ebolavirus infection. It’s not quite like you might think.

  If you devoured The Hot Zone when it was published, as I did, or if you have been secondarily exposed to its far-reaching influence on public impressions about ebolaviruses, you may carry some wildly gruesome notions. Richard Preston is a vivid writer, a skillful writer, an industrious researcher, and it was his purpose to make a truly horrible disease seem almost preternaturally horrific. You may recall his depiction of a Sudanese hospital in which the virus “jumped from bed to bed, killing patients left and right,” creating dementia and chaos, and not only killing patients but causing them to bleed profusely as they died, liquefying their organs, until “people were dissolving in their beds.”11 You may have shuddered at Preston’s statement that Ebola virus in particular “transforms virtually every part of the body into a digested slime of virus particles.”12 You may have paused before turning the page when he told you that, after death, an Ebola-infected cadaver “suddenly deteriorates,” its internal organs deliquescing in “a sort of shock-related meltdown.”13 You may not have noticed that meltdown was a metaphor, meaning dysfunction, not actual melting. Or maybe it wasn’t. At a later point, bringing another filovirus into the story, Preston mentioned a French expatriate, living in Africa, who “essentially melts down with Marburg virus while traveling on an airplane.”14 You may remember one phrase in particular, as Preston described victims in a darkened Sudanese hut: comatose, motionless, and “bleeding out.”15 That seemed to be so different from just “bleeding.” It suggested a human body draining away in a gush. There was also the statement that Ebola causes a victim’s eyeballs to fill up with blood, bringing blindness and more. “Droplets of blood stand out on the eyelids: You may weep blood.16 The blood runs from your eyes down your cheeks and refuses to coagulate.” The mask of red death—where medical reporting meets Edgar Allan Poe.

  It’s my duty to advise that you need not take these descriptions quite literally—at least, not as the typical course of a fatal case of Ebola virus disease. E
xpert testimony, some published and some spoken, tempers Preston on several of these more lurid points, without diminishing the terribleness of Ebola in terms of real suffering and death. Pierre Rollin, for instance, now deputy chief of the Viral Special Pathogens Branch of the CDC, is one of the world’s most experienced ebolavirus hands. He worked at the Pasteur Institute in Paris before moving to Atlanta, and has been a member of response teams to many Ebola and Marburg outbreaks over the past fifteen years, including those at Kikwit and Gulu. When I asked him, during an interview in his office, about the public perception that this disease is extraordinarily bloody, Rollin interrupted me genially to say: “—which is bullshit.” When I mentioned the descriptions in Preston’s book, Rollin mockingly said, “They melt, splash on the wall,” and gave a frustrated shrug. Mr. Preston could write what he pleased, Rollin added, so long as the product was labeled fiction. “But if you say it’s a true story, you have to speak to the true story, and he didn’t. Because it was much more exciting to have blood everywhere and scaring everywhere.” A few patients do bleed to death, Rollin said, but “they don’t explode, and they don’t melt.” In fact, he said, the conventional term then in use, “Ebola hemorrhagic fever,” was itself a misnomer, because more than half the patients don’t bleed at all. They die of other causes, such as respiratory distress and shutdown (but not dissolution) of internal organs. It’s for just these reasons, as cited by Rollin, that the WHO has switched its own terminology from “Ebola hemorrhagic fever” to “Ebola virus disease.”