by The Pandemic Century- One Hundred Years of Panic, Hysteria
Perhaps the only disease that compares to Ebola for visual shock value is yellow fever, which in acute cases can also cause bleeding of the mouth, eyes, and the lining of the gastrointestinal tract, as well as the production of a viscous black vomit from the stomach. However, while Ebola is sometimes horrifying to behold, bleeding only occurs in around half of the cases; diarrhea is a far more common symptom. Compared to HIV and SARS, it is also not that contagious. Ebola patients only become infectious when they develop symptoms—typically two to twenty-one days after exposure—and on average one Ebola patient will infect just two other people. By contrast, with HIV and SARS, the reproduction rate rises to four, and for truly catchy diseases such as measles, that number is eighteen.
Nevertheless, in previous outbreaks in the Democratic Republic of the Congo (DRC) and other countries in Central Africa, Van Herp knew that Ebola had been associated with mortality rates as high as 90 percent. Then, as in 2014, there had been no vaccine, nor were there any approved treatment drugs. Instead, doctors’ only option was to connect patients to an intravenous drip and keep them hydrated with fluids until such time as their immune system managed to defeat the virus. The problem is, while Ebola is not all that communicable, the disease is highly infectious—a cubic centimeter of blood contains one billion copies of the virus—and the attachment of an IV-line can result in blood leaking uncontrollably from the site of a puncture. If the outbreak in Guinea-forestière was due to Ebola—and the hiccups strongly suggested to Van Herp that it was—it was imperative to immediately isolate patients and their contacts, as well as anyone handling infectious cadavers, and introduce strict barrier nursing controls in hospitals. The problem was that as soon as news got out that MSF suspected Ebola, there would be panic across the region, not least among the organization’s staff in Guéckédou, none of whom had experience with the pathogen. On the other hand, Van Herp knew that, other than a case in Côte d’Ivoire in 1995 involving a Swiss zoologist, Ebola had never been detected in West Africa before. Nevertheless, until such time as diagnostic tests could be conducted, Van Herp thought it best to err on the side of caution. “After further examination, I said to my colleagues, ‘We’re definitely dealing with viral haemorrhagic fever, and we should be prepared for Ebola, even if never seen in this region before.’ ”
Van Herp was right to say that Ebola had never been seen in Guinea, but wrong to think that no one had previously suspected its presence in West Africa. In 1982, German scientists examined blood from hundreds of Liberians in Lassa-endemic rural areas of the country. Rather than simply testing for Lassa, however, they also looked for Ebola and a related filovirus called Marburg—so called because it was first isolated in the German town of Marburg in 1967—using a fast and inexpensive microscopic test known as indirect immunofluorescence.* They found antibodies to Ebola in 6 percent of the samples. Similar rates were also found in samples from Guinea and Sierra Leone. However, because the test depended on skilled interpretation and sometimes resulted in false positives, few experts took much notice. This was followed in 1994 by the infection of the Swiss zoologist. The zoologist most likely contracted Ebola when she performed a necropsy on a chimpanzee that had been found dead in Tai National Park, near Côte d’Ivoire’s border with Liberia, but there was no further transmission and, after being flown to Switzerland for treatment, she recovered. Then, in 2006, a group of medical researchers made a further intriguing discovery at Kenema General Hospital, in eastern Sierra Leone, not far from the Guinean border. As in Liberia, the researchers had decided to run a quick antibody test on blood from patients who had presented at the hospital for Lassa Fever. Previously, one-third of these patients had tested negative for Lassa, leading the researchers to suspect they were infected with another type of hemorrhagic fever, or possibly a mosquito-borne virus, such as dengue or yellow fever. To their surprise, of four hundred samples taken between 2006 and 2008, nearly 9 percent tested positive for Ebola. Not only that, but when they ran a more sophisticated assay, the researchers also saw that most of the antibodies were against Zaire ebolavirus, the most virulent of the five strains of Ebola. Zaire ebolavirus had previously been found in only three countries: the DRC, the Republic of the Congo, and Gabon. How the Zairean strain had come to be in Sierra Leone, 3,000 miles northwest of its endemic center of transmission, was a mystery. Nevertheless, the researchers thought the findings worth publishing and in August 2013 submitted a paper to the CDC’s journal, Emerging Infectious Diseases. As the research was a collaborative effort between the US Army Medical Research Institute of Infectious Diseases (USAMRIID) and Tulane University, the lead investigator, Ronald J. Schoepp, was reasonably confident the paper would be accepted. But after waiting nearly a year for a reply he was told it had been rejected; the final reviewer informed Schoepp, “I don’t believe there is Ebola virus in West Africa.”
By the middle of March, MSF’s senior leadership in Geneva was sufficiently alarmed by the reports from Guéckédou to dispatch three medical teams to the area. One was a team from Sierra Leone trained in the containment of viral hemorrhagic fevers. They arrived in Guéckédou on March 18 and immediately set about securing the area. Van Herp joined them soon after and began touring nearby communities to track the infection and raise awareness. Unfortunately, there was no laboratory in Guinea equipped to handle Ebola, much less to run sophisticated tests for detection of a filovirus, so blood samples were shipped all the way to the Institut Pasteur in Lyon. There, in a secure biosafety level 4 laboratory, Sylvain Baize, a specialist in hemorrhagic fevers who had previously worked in Africa, ran the critical assays that, on March 21, confirmed the presence of Ebola in several of the blood samples. It was too early to say which strain of Ebola was responsible—that would require more sophisticated tests using specific assays for each of the five strains—but the Pasteur Institute’s finding was sufficient to convince the Guinean government it had a problem. On March 22, Guinea’s Ministry of Health made the news public and the following day the WHO followed suit, declaring that it had been notified of a “rapidly evolving outbreak of Ebola virus disease in forested areas of south-eastern Guinea.”
The announcement could not have come at a worse time for the WHO. After its success containing SARS, the United Nations organization suffered deep budget cuts due to the global recession that had begun in 2008. The result was that by 2014, 130 members of GOARN had been laid off, leaving the WHO with a skeleton crew in the event of an emergency. WHO’s management was already monitoring concurrent outbreaks of bird flu in China, the MERS coronavirus in Saudi Arabia, and polio in war-torn Syria. In addition, there were ongoing military and humanitarian crises in the Horn of Africa and the Sahel region of Africa. Set against these problems, an outbreak of Ebola in a remote forested region of Guinea that had so far triggered just twenty-three deaths struck officials in Geneva as small beer. Besides, as the WHO’s press spokesman Gregor Hartl tweeted on March 23: “There has never been an Ebola outbreak larger than a couple of hundred cases.” Two days later Hartl went further, insisting that “Ebola has always remained a localised event.”
Not everyone shared Hartl’s complacency. The following day in an emergency teleconference involving officials in the WHO’s Africa Regional Office (AFRO) and emergency directors in Geneva headquarters, WHO personnel warned that the outbreak in Guinea-forestière was spreading faster than anyone had anticipated and there was a “high possibility of cross-border transmission.” Worried that the deaths of health workers were an indication that barrier nursing controls in hospitals were inadequate and that there was a risk of the outbreak being amplified, the officials recommended raising the WHO’s alert to Grade 2, the second highest level possible. Instead, senior officials in Geneva decided to keep the alert at Grade 1 and deploy a multidisciplinary team, comprising thirty-eight individuals, to Guinea to supervise infection control measures and help with surveillance and case tracking. By now, MSF was also hearing of suspected cases across the border in Foya, in northern Liberia
. Then came reports of a case in Conakry. For Van Herp, the appearance of Ebola in Guinea’s coastal capital four hundred miles to the west of Guéckédou was clear evidence of the “unprecedented” geographic spread of the virus. His statement infuriated Guinea’s minister of health, Colonel Rémy Lamah, who responded by instructing officials to record only laboratory-confirmed cases of the disease, thereby allowing suspected cases and contacts of suspected cases to go unreported. This policy would come back to haunt the WHO when official figures from Guinea showed a fall in case numbers in the last week of April, leading observers to believe that the worst was over.
NO ONE KNOWS for sure if bats are the natural reservoir of the Ebola virus. To date the only live filovirus that has been recovered from bats is Marburg. However, in surveys conducted in Ebola-stricken areas of Gabon and the Republic of the Congo, Ebola antibodies and fragments of Ebola RNA have been recovered from three species of fruit bat. One of these, the hammer-headed bat, Hypsignathus monstrosus, is routinely hunted as a source of protein. Coupled with the isolation of Marburg from the Egyptian fruit bat, Rousettus aegypticus, this lends support to the theory that bats are the virus’s natural reservoir and the main source of human infections. However, gorillas and chimpanzees are also known to be infected with Ebola and Marburg from time to time, and on occasion, they suffer dramatic die-offs, so it is possible they could also transmit the viruses to humans. In 1967 an outbreak of Marburg in a consignment of African green monkeys shipped from Uganda to vaccine research laboratories in Germany and the former Yugoslavia sparked thirty-seven infections leading to the deaths of seven laboratory workers. In 1994 a Swiss zoologist in Côte d’Ivoire almost certainly contracted Ebola from a monkey that had died in the forest. Then, in 1996, nineteen people in Mayibout, Gabon, were infected with Ebola after butchering and eating a chimpanzee they had discovered on the forest floor. Similar outbreaks in humans following extensive deaths of chimpanzees and gorillas have been documented in the Republic of the Congo. On the other hand, the high case fatality rates recorded in apes, combined with their declining geographic range, indicate that they are likely dead-end hosts for the virus and therefore not the primary reservoir for Ebola.
To date, five strains of Ebola have been identified, each name corresponding to the place where it was first isolated. The first two species, Zaire ebolavirus and Sudan ebolavirus, were discovered in near simultaneous outbreaks that occurred in 1976 in Yambuku and Sudan respectively. While the Sudan outbreak was traced to a worker in a cotton factory, in Yambuku the index case was a male instructor at a Belgian Catholic mission school who had bought fresh antelope and monkey meat on his way to the village, suggesting the outbreak had a zoonotic origin. The following year, a nine-year-old girl died of Ebola at Tandala Mission Hospital, in Zaire, but no one else in her family was infected and the virus spread no further. This was followed, in 1989, by the isolation of a third species, Reston ebolavirus, during an outbreak that occurred at a primate quarantine facility in Reston, Virginia. That outbreak was blamed on a shipment of wild monkeys—long-tailed macaques—that had been imported to the United States from the Philippines for use in animal research. However, although the outbreak resulted in four subclinical infections in laboratory workers, no humans died, suggesting that the Reston strain did not present a disease risk to humans. The fourth species, Côte d’Ivoire ebolavirus, was the one isolated from the Swiss zoologist in the Tai Forest in 1994. The fifth and final subtype, Bundibugyo ebolavirus, was named after a small outbreak in the Bundibugyo district of western Uganda in 2007, in which just 30 people were killed (by contrast, seven years earlier, an outbreak of Zaire ebolavirus in Gulu, Uganda, resulted in 425 cases and 224 deaths). In addition, in 1995 there was an outbreak of Zaire ebolavirus in Kikwit, a city in the DRC with a population of 400,000.
The sporadic appearance of Ebola coupled with the genetic variation between the different subtypes is both a puzzle and a challenge to viral ecologists. On average the genomes of each species show a 30 to 40 percent divergence, suggesting that each subtype has evolved in a different animal reservoir or occupies a different ecological niche. Moreover, as no one knows where the virus goes between outbreaks or the evolutionary history of the different strains, it is impossible to say why some, such as Zaire ebolavirus, are especially lethal to humans, while others, such as Bundibugyo ebolavirus, are associated with far lower rates of mortality. The fact that so much about Ebola remains shrouded in mystery underlines the importance of paying attention to factors that are known to increase the risk of infection and that lie within human control. One of these is the consumption of bushmeat. The other is social behaviors and cultural practices. In the context of West Africa, perhaps none is more significant than the rituals surrounding death, mourning, and burial. These rituals are informed by Christian and Muslim religious beliefs as well as people’s subscription to sodalities or secret esocieties. Although few outsiders have gained access to these societies, it is known that their members worship ancient bush spirits that are thought to reside in the forest and are usually represented by a masked figure that is part crocodile, part human. For instance, during the initiation into Poro, as the traditional men’s society is known, young boys are led into the forest to be “eaten” by the masked bush spirit, after which they undergo circumcision and ritual scarification. Female initiates into the women’s society, Sande, undergo similar ritual scarification, as well as, on occasion, genital mutilation.
Peoples’ subscription to such societies, however, is probably far less important than syncretistic beliefs and practices, including mortuary practices, designed to ensure that the deceased are reunited with their ancestors in the afterlife. For the Kissi and other ethnic groups indigenous to the region, including the Mende and Kono, this so called “village of the ancestors” is not like the Christian idea of heaven or hell—how people have conducted themselves on Earth has no bearing on their destiny in the afterlife. Rather, it is determined by the accomplishment by the living of certain mortuary practices that are owed to the dead. These include washing and dressing the corpse, a practice that is repeated twice, first when the corpse is initially clothed or wrapped in a fine cloth, and second when it is reclothed for burial (usually in a cheaper material). These rituals may also include treatments and sacrifices to dispel angry spirits or to address imagined acts of “sorcery” and “witchcraft.” Such rituals assume even more significance when an Ebola patient collapses in a remote rural area and is removed to an Ebola Treatment Unit (ETU) many miles from their home village. If these rituals are not performed in the prescribed manner, or crucial steps are missed, it is thought that the deceased will be condemned to wander eternally, in which state they will visit curses upon their family and community—something survivors fear more than Ebola itself.
Finally, in times of sickness, it is common for local people to turn to zoes or traditional female healers for help. Sometimes these healers will treat the sick with herbal remedies. On other occasions they may touch them and offer magical incantations in an effort to dispel the “evil spirits” that are thought to be the source of the affliction. In the case of Ebola, of course, such practices represent a considerable infection risk. Washing and touching the bodies of Ebola cadavers is similarly dangerous, as studies have shown that Ebola can persist in blood and organs for up to seven days after death.
PERHAPS NO ONE knows more about the significance of these traditions and the challenges they present for the management of Ebola in rural areas of Africa than Jean-Jacques Muyembe-Tamfum. A short, vital man who always seems to be on the point of breaking into a grin, Muyembe is the director of the National Institute for Biomedical Research (INRB) in Kinshasa, and has attended more Ebola outbreaks than any other scientist alive. Known in his home country as “Dr. Ebola,” Muyembe points out that bushmeat is a traditional part of Africans’ diet, which is why, rather than seeking to ban the practice, he supports efforts in the DRC to train hunters to butcher and prepare carcasses safely. He is a
lso critical of Ebola control measures such as mandatory cremations and bans on burial rituals. “By seizing their cadavers we hurt people’s spirit,” he explained.
Muyembe’s first encounter with Ebola came during the 1976 outbreak at Yambuku, although, like other people involved in the response to the mysterious illness at the Belgian mission hospital, he had no idea at the time that he was dealing with a new filovirus. “We heard that a lot of people were dying, even the Catholic sisters,” he said. “The minister of health ordered me to go there and assess the situation.” At the time, Zaire was ruled by the dictator Joseph Mobutu, and when Muyembe, then a young professor of microbiology at Kinshasa Medical School, was told Mobutu had offered the use of his private jet, he realized he had no choice in the matter. He arrived at the mission late in the evening after a grueling four-hour journey by jeep from the nearest landing strip to find that all the staff had fled and the wards were deserted save for a single sick child. “The mother said it was malaria but I think it was probably Ebola because the child died in the night.” The next day, he awoke to find the hospital full of anxious villagers, many of whom were also feverish.