This article by Melissa Leach, STEPS Centre director, appeared in Wellcome History 38 (Summer 2008).

Haemorrhagic fevers capture popular imagination as deadly zoonotic diseases that come ‘out of Africa’. Ebola, lassa and other viral haemorrhagic fevers that are associated with wildlife vectors in forested environments figure prominently in current concerns about so-called ‘emerging infectious diseases’, their hotspots of origin, and threat of global spread. Outbreaks attract rapid international control and policy responses.

This ‘outbreak narrative’ (Wald 2008) is only one amongst several storylines about haemorrhagic fevers, however. Other narratives present contrasting views concerning their causes, dynamics, significance and control. Narratives matter because they shape the responses of health institutions and others. In this short article I outline three other narratives which highlight shortcomings in dominant, epidemiologically-driven outbreak responses, and which might offer pointers towards more effective ways of dealing with haemorrhagic fevers.

Media and fictional sensationalisation helped entrench the first, global outbreak narrative following the first recorded outbreak of Ebola in 1976 in DR Congo. The global threat from this ‘rapid killing’ disease (50-90% of people afflicted die) caused by a filovirus with a little-understood animal reservoir in central African forests was elaborated in Garrett’s 1994 The Coming Plague and Preston’s 1994 The Hot Zone as well as the 1995 blockbuster film Outbreak. Lassa haemorrhagic fever, identified by scientists in Sierra Leone in the 1980s to be caused by an RNA virus whose animal reservoir is a rat, Mastomys natalensis, has a lower mortality rate (80% of cases are asymptomatic and 1-15% of clinically diagnosed cases die). Yet in the forested countries of Sierra Leone, Guinea and Liberia about 5,000 people die from it annually. As with ebola, global outbreak narratives emphasise its threat among globalising and urbanising populations, and biological warfare.

A second narrative takes a more local focus, constructing haemorrhagic fevers as devastating disease events affecting local populations in African settings, requiring a universal kind of rapid response by external agencies. Thus the outbreak alert and response programmes to ebola of the World Health Organization and Centres for Disease Control from the 1990s established a standardised set of medical and public health strategies to contain the disease. These centred on establishing isolation units for the infected and implementing barrier nursing techniques; tracking and controlling those who had had contact with infected individuals; health education, and limiting ‘dangerous’ local behaviours such as the washing and burial of corpses. The narrative generally presents local Africans as ignorant, and mired in negative cultural practices. Not much reported, however, is that such top-down control measures often meet with resistance. In Gabon in 1995-6, for example, American and French ebola control measures were perceived as so inappropriate and offensive by villagers that they aroused deep suspicion, and international responses to a further outbreak there in 2001 met with fierce local armed resistance. Vaccination is potentially a highly effective measure, but within this narrative of ‘external control of local disease’, pharmaceutical companies have little interest in funding vaccines for a disease of poor African populations. Vaccines against haemorrhagic fevers have indeed remained elusive. Filoviruses and RNA viruses offer particularly complex scientific challenges, and there are uncertainties about vaccine efficacy and side-effects in these disease contexts. A promising lassa vaccine had to be halted in early trials, for example, when its vector was found to cause vaccinia infection in HIV-infected people.

In a third and contrasting narrative, haemorrhagic fevers are seen as long-present amongst local populations who have developed culturally-embedded ways to live and deal with them. Local knowledge and cultural logics can, so the argument goes, inform and be integrated into response strategies, helping to make these more context-specific, locally appropriate and acceptable. The work of anthropologists Hewlett and Hewlett (2008) has been pivotal in developing this narrative, and in its uptake by the WHO which from 2001 came to include anthropologists in integrated ebola response teams. Anthropological perspectives help identify valuable, health enhancing local knowledge and cultural categories which can be blended productively with scientific knowledge. In Uganda, for example, these included the coexistence of both endemic and epidemic (‘gemo’) models of disease. As an ebola outbreak progressed, the shift in local understandings to their gemo framing triggered elaborate social protocols to control the disease, and these were successfully integrated into responses. This narrative also offers ways to understand local resistance and adapt accordingly – as for instance in DRC in 2001 when the high screens used to hide victims’ bodies were found to contradict funeral norms. It can build more effective, dialogue-based health education. Non-governmental organisations addressing lassa fever in Sierra Leone in the late 1980s used participatory theatre to build on local understandings of the risks of contact with rat excreta, for example. Compared with ebola, anthropological studies of lassa fever are lacking. Yet understanding local categories and fears would assist with several current challenges: encouraging more cases to be identified early and brought to hospital, and addressing prevalent anxieties that hospital lassa treatments themselves ‘kill’ (Merlin 2002). Overall, this narrative emphasises the need for responses to be adapted to local circumstances. Context matters, and technologies and practices suited to one place might be rejected in another.

For all their contrasts, these narratives share a focus on short-term responses to haemorrhagic fevers. Different again is a fourth narrative that turns attention to longer-term ecological and social dynamics and more structural shifts that may be impinging on the nature and frequency of outbreaks, and on regional vulnerability to them. Evidence that ebola outbreaks are increasing in frequency and severity underlines the relevance of such longer-term perspectives. Some virologists now argue that identifying and addressing the underlying causes of the emergence of infectious diseases is vital to interrupt potentially dangerous cycles of viral-animal-human co-evolution. Within a narrative of long-term dynamics, one line of argument would focus on the poverty, inequality and ‘structural violence’ (Farmer 2003) in regions where haemorrhagic fevers are rife. Declining health systems and overcrowded hospitals in which viruses multiply are one manifestation of this. Conflict is another, as in West Africa where a decade of civil war closed the lassa research unit in Kenema, Sierra Leone and halted regional co-operation in the Mano River Union countries – only recently being rebuilt. In this view, tackling haemorrhagic fevers cannot be separated from tackling poverty and its causes, and building accessible and equitable health systems.

This narrative can also focus on long-term environmental dynamics. Thus deforestation through agriculture and logging, and its political, economic and poverty-related causes has been assumed to contribute to haemorrhagic fevers, by bringing populations closer to their forest animal viral reservoirs and secondary vectors. Yet many questions remain unresolved, and causative patterns uncertain. Ebola’s natural reservoirs and transmission cycle remain ambiguous, with competing theories – centred on bats and rodents – in play. Outbreaks of both ebola and lassa have often centred on the forest-savanna ecotone, suggesting (little understood) interactions with forest-savanna dynamics and land use, which will themselves be influenced by the uncertain effects of climate change. This narrative thus suggests a role for long-term ecosystem surveillance with interdisciplinary collaboration, including local knowledge of ecosystem-land use-vector dynamics. Yet it also suggests that full predictability and control of such ecosystem shifts and people’s interactions may be an illusory goal, so strategies may need to focus on more flexible, adaptive responses.

Each of these narratives – of global outbreak, of local disease event requiring external response, of local knowledge and cultural logics, and of long-term dynamics – thus constructs haemorrhagic fevers in different ways. They pick out different temporal and spatial scales; they use and validate different kinds of knowledge, and they assign cause, blame and vulnerability differently. Each suggests somewhat different pathways of response, involving different combinations of actors. Elements of each will undoubtedly have roles to play in the vital task of addressing haemorrhagic fevers in the decades to come, underlining the need for further elaboration of the understandings and strategies implied by each narrative, and identification of the conflicts, as well as potential complementarities, between them. This may also help redress a balance. So far, outbreak narratives and their central medical and epidemiological precepts have dominated the powerful international apparatus that orchestrates infectious disease responses. Might it be time for research drawing attention to local knowledge, culture and context, and to long-term social and ecological dynamics, to be drawn into dialogue with them, in ways that can lead to more sustainable and socially just pathways of disease response?

References

Farmer, P., 2003, Pathologies of Power: Health, human rights and the new war on the poor. Berkeley: University of California Press.

Hewlett, B. and B. Hewlett, Ebola, Culture and Politics: The anthropology of an emerging disease

Merlin, 2002, ‘Licking’ Lassa fever: a strategic review. London: Merlin (www.merlin.org.uk)