FROM ANONYMITY TO NOTORIETY. HISTORICAL PROBLEMS ASSOCIATED WITH OUTBREAKS OF EMERGING INFECTIOUS DISEASES; A CASE STUDY: EBOLA HAEMORRHAGIC FEVER. by Daniel K. Sokol A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Social and Economic History. University of Oxford September 2002 2 ACKNOWLEDGEMENTS When I shared my idea of conducting a survey among Ebola specialists with a fellow student, he predicted a final sample size of four. Thirty three surveys came back, some with remarkably detailed answers. I wish to thank all the 33 scientists who took the time to complete the survey. Many expressed a deep interest in this project and continued to e-mail me with ideas and contributions throughout the year. Special thanks to Dan Bausch, of the Centers for Disease Control, Cathy Roth and David Heymann, of the World Health Organization, Jean-Paul Gonzalez, of the Institut de Recherche et de Développement, Joel Breman, of the US National Institute of Health, Sue Fisher-Hoch, of the University of Texas School of Public Health, and Bill Close for dealing so patiently with my questions and requests. Thanks also to Barry Hewlett, of Washington State University, for his comments on the anthropological side of Ebola, and Jens Kuhn, for sharing his monumental knowledge on the virus and its history. Most of all, I express my gratitude for my genial supervisor Dr Helen Tilley, formerly of the Wellcome Unit for the History of Medicine in Oxford, and now of Princeton University, whose insights and suggestions were invaluable. I envy her future students. 3 ABSTRACT Ebola Haemorrhagic Fever is an acute viral disease with a lethality rate ranging from 50% to 90%. Although first reported in 1976, it only emerged in the public consciousness in the early 1990s. This work explains the reasons behind this sudden change, and examines the modifications that arose in the transition from scientific texts to popular articles. My analysis reveals that this newfound notoriety has had direct and indirect effects on the control and management of Ebola epidemics. The initial reactions of Europeans and Africans in epidemic sites are reconstructed using oral interviews, published material, as well as surveys sent to 33 Ebola researchers. Using this evidence, the thesis explores a variety of issues: how afflicted communities interpreted the outbreaks, the role of Western and traditional medicine, the various ways in which local populations resisted control measures, and the different attitudes of Western health personnel towards the disease and each other. The result is a deeper understanding of the considerable social impact of Ebola epidemics, and an awareness of certain problems entirely neglected by the media. Finally, this thesis turns its attention to the mystery surrounding the disease and to scientists’ attempts to solve some of the unknown elements, such as the identity of the natural reservoir. I argue that the scientific uncertainty has affected popular perceptions of the disease, and, as a result, increased the amount of funds invested into Ebola research. A section devoted to broader issues, such as the difficulty of reconciling deforestation and economic growth in impoverished African countries, and the deleterious effects of political instability, concludes the work. The thesis argues that the publicized drama of Ebola outbreaks has obscured these fundamental problems. 4 TABLE OF CONTENTS 1. Introduction 5 Background on Ebola 5 The Ebola Phenomenon 6 2. From Anonymity to Notoriety 8 The Puzzle of Ebola 11 The Spread of Ebola out of Africa 15 3. Face to Face (!) with Ebola 24 The African Response to Ebola Outbreaks 24 Western Health Workers’ Reactions to Ebola 37 4. An Epi(demi)c Mystery: In Search of Answers 44 Ebola and Scientific Uncertainty 45 Beyond the Reach of Science 51 5. Conclusion 56 Appendix 58 Bibliography 73 5 CHAPTER 1 Introduction ‘I will show you fear in a handful of dust’ T.S. Eliot, The Waste Land (1922) Background on Ebola Ebola Haemorrhagic Fever (EHF) is an acute viral illness with a lethality rate that ranges from around 50% to 90%. With the exception of Rabies and HIV/AIDS, no other viral disease has such a high case fatality rate. The Ebola viruses are one of two genera of the family Filoviridae.1 The symptoms of Ebola infection vary from case to case, but generally involve fever, headache, joint or muscle pains, sore throat, vomiting, diarrhoea, bleeding, shock and other neurological symptoms. Patients usually die six to nine days after the appearance of the first symptoms. At the time of writing, there exists no treatment against the disease. Transmission of the virus occurs through contact with infected blood or body fluids. One species of the genus, Reston Ebola Virus (REBOV), is believed to be spread by aerosol, but is nonpathogenic to humans. Despite a number of investigations, the organism in which the virus resides in nature - the reservoir – is not known.2 1 The other genus comprises the Marburg virus. There are four species of Ebola, named after the country or site of their first recorded appearance: Zaire, Sudan, Reston and Côte d’Ivoire Ebola Virus. 2 Colebunders, R., and Borchert, M., ‘Ebola Haemorrhagic Fever’, Journal of Infection, 40 (2000), 16- 20. 6 The first reported cases of EHF appeared in the Sudan and the Democratic Republic of the Congo (DRC) in the middle of 1976, when 602 people were reported to have contracted the disease. Since then, there have been about a dozen further outbreaks, totalling 1638 identified cases, and 1104 deaths (67% case fatality rate). It should be noted, however, that retrospective evidence of Ebola infections, as shown by Tignor et al., and the non-identified or misidentified cases are likely to make this total a gross underestimate.3 The new agent was named Ebola, after a river in northern DRC. The Ebola Phenomenon With 1104 documented deaths since 1976, and even if the figures are wrong by a factor of a hundred, Ebola is a statistically trivial disease. Malaria, for example, kills over two million people each year, and Tuberculosis makes three million victims annually.4 Yet ‘Ebola’ is a household name. It was not always so. One purpose of this thesis is to examine the immediate questions and observations raised by scientists on the nature of this new disease. Chapter one explains the disease’s meteoric rise in the early 1990s from anonymity to notoriety in the public consciousness. The consequences of this rise to fame are also discussed. The second chapter deals with the reactions of Africans and Westerners to Ebola outbreaks. Using extracts from a survey conducted among 16 field epidemiologists and 17 laboratory researchers, all of whom have worked with the virus, as well as 3 Tignor et al.’s study, based on serological evidence, claims that victims of a Yellow Fever epidemic ravaging parts of Ethiopia in the early 1960s died not only of Yellow Fever, but also of Ebola. Some scientists, however, question the findings, as Tignor used error-prone indirect immunofluorescence tests to obtain the results. Tignor, G., et al., ‘The Yellow Fever Epidemic in Ethiopia, 1961-2’, Transactions of the Royal Society of Tropical Medicine and Hygiene, 87 (1993), p. 162. 4 World Health Organization Fact Sheet Number 189. Available Online: http://www.who.int/inf- fs/en/fact189.html 7 personal communications and published material, chapter two reconstructs the actions and reactions of victims, community members and health personnel in the field.5 The result is a vivid tableau of what occurred during past outbreaks, and a deeper understanding of the immediate social impact of Ebola epidemics. A detailed summary of the survey results is included in the Appendix. Finally, we shall turn our attention to the mystery surrounding Ebola, and the broader issues associated with the disease. We follow the elusive search for the reservoir, the debate on the underlying causes of the epidemics, and the effects of politics on African governments’ responses to Ebola outbreaks. What becomes apparent is that the scientific uncertainty complicates an already elaborate web of issues surrounding Ebola. Unlike firmly established diseases such as Cholera, Plague and Yellow Fever, Ebola is a recent addition to the pantheon of dreaded afflictions. This thesis attempts to untangle strands of the ‘Ebola web’, and to illuminate neglected aspects of the disease’s history. 5 Between March and July 2002, two different surveys were sent to field and laboratory scientists. As promised to the respondents, their identity is undisclosed. Certain scientists have given me information on the condition of anonymity. Citations from these sources will be referenced simply as ‘Personal Communication’. 8 CHAPTER 2 From Anonymity to Notoriety The Ebola virus has been lurking in the forests of Africa for thousands of years, contained within a still unknown reservoir.6 Before 1976, the year the virus left its niche to infect 602 human cases in the Sudan and the Democratic Republic of the Congo (DRC), Ebola was probably responsible for the sporadic deaths of both human and non-human primates for centuries. A recent serological study has shown that some Pygmy populations and farmers of the Central African Republic possess filovirus antibodies in their blood, suggesting previous encounters with Ebola and Marburg. 7 Following the reported eruptions of Ebola in the late 1970s, a haemorrhagic fever surveillance program was conducted in the DRC between 1981 and 1985. The program led to the identification of 21 cases of Ebola. These few cases, which would probably have passed unnoticed in the absence of surveillance, provide evidence that small-scale and self-limiting outbreaks of Ebola have been occurring in the past. It is easy to imagine, in areas of very low population density, a hunter entering the forest, contracting the disease through the bite or blood of an infected animal, and in turn transmitting the disease to the rest of his family. The 6 Suzuki, Y., and Gojobori, T. ‘The Origin and Evolution of Ebola and Marburg Viruses’, Molecular Biology and Evolution, 14, 8 (1997), 800-806. 7 Gonzalez, J-P., et al. ‘Ebola and Marburg Virus Antibody Prevalence in Selected Populations of the Central African Republic’, Microbes and Infection, 2 (2000), 39-44. 9 outbreak would stop at the hunter’s doorstep, and would not be reported to the health authorities. Chimpanzees and gorillas have also been victims of Ebola. As early as 1931, Charles Elton, an Oxford zoologist, stressed the importance of studying animal epidemics. Such studies, he argued, would allow us to trace human diseases to their reservoir in the wild and to examine the forerunners of an epidemic. In short, they would provide a greater understanding of the mechanisms underlying epidemics in general.8 At the close of the 20th century, the rise in emerging infections meant a leap out of obscurity for the disease ecology of animals. The possibility of total species extinction through disease, long thought nonsensical in terms of population biology, is perhaps the most notable - and alarming - finding.9 In 2002, the US Institute of Medicine published a report on the emergence of zoonotic diseases, pointing to the avalanche of emerging zoonotic infections of the last decade, and addressing the need for better prevention and control strategies to combat such diseases.10 The death of non-human primates has often preceded outbreaks of human disease. The human epidemic of Kyasanur Forest disease in India (1957), for example, was announced by an unusually high number of monkey deaths.11 In many African countries, monkeys are commonly hunted for food and trade and present a risk of infection to humans. Peeters et al. analyzed the blood of 788 monkeys captured in the 8 Elton, C., ‘The Study of Epidemic Diseases Among Wild Animals’, Journal of Hygiene, 31, 4 (1931), 436-437. 9 Daszak, P. ‘The Emergence of Infectious Diseases Among Wildlife’, International Conference on Emerging Infectious Diseases 2002, Atlanta, USA, 25 March 2002. Daszak cites Australian gastric brooding frogs, Hawaiian birds and Partula tree snails as examples of total species extinction through disease. 10 Burroughs, T., Knobler, S., and Lederberg, J. (eds) The Emergence of Zoonotic Diseases (Washington D.C., 2002). 11 Banerjee, K., ‘Emerging Viral Infections with Special Reference to India’, 103 (1996), 177-200. 10 rainforests of Cameroon. They found that 13 of the 16 monkey species were infected with Simian immunodeficiency virus (SIV), including four species not previously known to harbour the virus. They conclude that ‘humans who hunt and handle bushmeat are exposed to a plethora of genetically highly divergent viruses’.12 Dr William Karesh, of the Wildlife Conservation Society, estimates that humans and great apes commonly share 150 diseases.13 Yet there exists evidence of possible longstanding knowledge of the dangers of primate bushmeat, or at least cases when the consumption of such meat is forbidden. In 1933, Humphrey Gilkes, a medical officer working in Zambia, published an article on native customs in Africa. Writing on the tribes living near the Luangwa valley in Northern Rhodesia (now Zambia), he notes that people of child-bearing age must not eat the ‘flesh of monkeys because it will make their children be born mad’.14 Such a rooted taboo, associating monkey meat with infant dementia, suggests that monkey pathogens were transferred to man at some time in the population’s history. On a number of occasions, the deaths of monkeys preceded or co-occurred with human outbreaks of Ebola, including one instance where a 34-year-old ethologist was directly infected after performing an autopsy on a wild chimpanzee.15 A month later, in December 1994, the first reported outbreak of Ebola erupted in Gabon. On arrival at the site, investigators received reports of unexplained deaths among gorillas and great apes, although they found no carcasses. In February 1996, before the second epidemic in Gabon, 18 people who had skinned and chopped a dead chimpanzee fell 12 Peeters et al. ‘ Risk to Human Health from a Plethora of Simian Immunodeficiency Viruses in Primate Bushmeat’, Emerging Infectious Diseases, 8, 5 (2002), p. 451. 13 Personal Communication, 16 August 2002. 14 Gilkes, H. ‘Native Customs in Africa and the Medical Officer’, Transactions of the Royal Society of Tropical Medicine and Hygiene, 28, 3 (1933), p. 319. 15 Formenty, P., et al., ‘Ebola Virus Outbreak Among Wild Chimpanzees Living in a Rain Forest in Côte d’Ivoire’, The Journal of Infectious Diseases, 179 (supplement 1, 1999), S120-S126.