Thursday, 10 April 2014

Ebola in Guinea – people, patterns and puzzles

setting up traps in the mining areaMelissa Leach and team set up rat traps as part of their multidisciplinary research into emerging zoonoses in West Africa

The francophone West African country of Guinea doesn't often make international headlines, but has this week for the nastiest of reasons. An outbreak of Ebola, first identified in the forested south-east of the country in mid-March, has now spread across the country to take hold in the coastal capital, Conakry, where at least six cases have been diagnosed.This is the first recorded West African outbreak of this rapid-killing haemorrhagic fever, which since the 1990s has been associated with a series of epidemics in Central and East Africa. The virus in Guinea is the Zaire type, which has a 90 per cent fatality rate. So far more than 70 people have died, making this the deadliest outbreak since 2007, when 187 people died in the Democratic Republic of Congo.

This is devastating news for people in Guinea – a country I've lived and worked in over many years. But it's not just a sense of personal connection with tragedy that prompts these reflections, nor the fact that Ebola is a zoonotic disease closely related to those we're currently studying in the Dynamic Drivers of Disease in Africa Consortium. It is also because this outbreak raises intriguing patterns and puzzles that encourage us to ask new questions about zoonotic disease emergence in general, and what may be happening here in particular.

This may be Guinea's first experience, but there is much about the pattern of this outbreak – and the international community's response to it – that is typical of experiences with Ebola elsewhere.

First, Ebola is being highlighted as an "exceptional" disease – one well-worthy of dramatic political and public attention. Its unusualness, epidemic and rapid-killing form contribute to this, in contrast with more mundane diseases – malaria, pneumonia, diarrhoea – that more regularly afflict Guinea's women, men and children, but rarely make the news.

Outbreak narrative of emerging infectious diseases

Second, accounts of this episode closely fit a global "outbreak narrative" that has come to typify international accounts and responses to so-called 'emerging' infectious diseases. As Patricia Wald puts it in her 2008 book Contagious, this narrative "begins with the identification of an emerging infection, includes discussion of the global networks throughout which it travels, and chronicles the epidemiological work that ends with its containment" (Wald 2008: 2). Typically, too, origins are associated with a remote, rural place and the practices of its (often poor) inhabitants, from which infection emerges into urban areas and then to threaten the world. This is a narrative about mobile microbes and people in a mobile world.

All these narrative elements are present in accounts of Ebola in Guinea: the likely reservoir of the virus in bats in the forests of the south-east; likely "spillover" transmission to someone in a rural setting (whether hunting, eating or otherwise coming into contact with an infected bat or an infected ape – there has been speculation about all these); the first diagnosed case in a senior hospital doctor in the rural town of Gueckedou; spread to health workers and to kin attending his funeral, and thus to the town of Macenta; and now, through kinship, trade and transport networks, spread to the capital.

Fears of the outbreak "going global" were voiced last week when a Canadian who had recently visited Guinea was suspected to have the disease – although this turned out not to be the case.  Meanwhile, publics and authorities in Liberia, Sierra Leone and Senegal fear that the virus will travel rapidly across Guinea's international borders, following the multiple movements of people for festivals and visits, livelihoods and trade, that are part of life in this region. Indeed Senegal has now closed its border, with its Ministry of the Interior ordering all movements of people through the southern boundary to Guinea to be suspended indefinitely to prevent the spread of the disease.

Disease as a security threat

Third, and again typical, this Ebola outbreak is couched as a security threat. In a move that aligns with a broader international "securitisation" of infectious disease in recent years, the Economic Community of West African States (Ecowas) has called for international help to thwart the "serious threat" it poses to regional security.

There is nothing inherently "untrue" about this global outbreak narrative, and coupled with security concerns it may help to pull international agencies, effort and resources to Guinea. Indeed, this is already happening, in the rapid-response efforts of international NGOs Plan International and Doctors without Borders, and the rapid mobilisation of scientific networks for diagnostics – including the Lassa Fever laboratories in Kenema Government Hospital, one of our partners in the Dynamic Drivers of Disease in Africa Consortium. However this pattern of narrative and response does downplay some other aspects of disease dynamics, that might be worthy of more attention.

The poverty connection

One is the relationship between Ebola and poverty. South-east Guinea, despite its rich mineral resources, is an economically poor region by any standards. The living conditions of many of its people and the state of its health services reflect this. While the Ebola virus knows no class boundaries – Guinea's first few cases spread amongst a relatively elite doctor's family, after all – poverty-linked livelihood practices and overcrowded health facilities have undoubtedly been part of its dynamics. Meanwhile, the impact of a sudden, rapid-killing virus, awful anywhere, can easily feed into a worsening spiral of impoverishment for rural and urban people already struggling to cope with low incomes and myriad other health problems. Where each family member contributes vitally to a family livelihood, loss of one is an economic and social as well as a personal tragedy.

Second, the narrative of rapid, sudden emergence of a disease like Ebola can overlook longer histories of interaction, which can in turn offer valuable clues as to how to deal with it. In central and eastern Africa, the idea that Ebola is novel has been found wanting. Scientists have found antibodies suggesting that human populations may long been been exposed to Ebola. Anthropologists such as Barry Hewlett have shown that local populations have long been aware of the disease, and have their own cultural logics to explain it and social protocols to deal with it. These include practices of isolation and care that have proved so effective that agencies such as the WHO have incorporated them into their response strategies.

The value of local knowledge

Ebola control efforts that in the 1990s relied solely on top-down, expert interventions, and were sometimes resisted and resented for their injustices, are now much better integrated with local knowledge and responsive to community concerns. NGO and government agencies now attempting to control Ebola in Guinea might pay heed to these experiences. Are Guinea's populations entirely ignorant of Ebola and needing to be educated by outside experts, as is being assumed? Or might there be relevant and useful local knowledge and experiences to be tapped into, out in those remote forest villages?

Certainly Ebola was described as an unknown, strange illness ("une maladie étrange") by the nationals first reporting it to the Guinean press. But these were urban residents, with elite perspectives. What of Guinea's rural inhabitants? Has anyone explored? Would participatory modelling, of the kind we have been doing in the Drivers of Disease Consortium, yield any alternative, and perhaps valuable, perspectives? This is the first of the puzzles that, to me, needs to be addressed.

Environmental dynamics

The second is more intractable, and concerns the relationship between this outbreak and environmental change. The scientific struggle to find the reservoir host of the Ebola virus has been long, and is not yet concluded (though there is good evidence for it in bats, in West Africa as elsewhere). Environmental modellers have associated outbreaks with forested environments, and with particular seasonal conditions. But this still leaves the question – why a major outbreak in Guinea now? And why has this part of West Africa escaped, until now, the outbreaks that have afflicted east and central Africa?

It could be that Ebola is more ancient in the region than scientists and authorities have realised, but has been dealt with quietly in remote forests, rather than "emerging" to wider public attention – so the current epidemic is an epidemic of diagnosis rather than of disease. It could be that the region's bat populations have only recently acquired the virus.

Bat-human interaction

Or it could be that they have long had it, but spillover to humans is more recent. Here, an environmental narrative sometimes circulates around Ebola and other haemorrhagic fevers. This assumes that once-extensive forests in which bats lived, separately from humans, have undergone progressive deforestation under the influence of population growth, land use and climate change. As bat habitats have fragmented and as people have moved into once-pristine forest areas, so human-bat contact has increased, making viral spillover more likely.

While it sounds plausible, however, such a linear narrative is hard to apply convincingly to south-east Guinea. While many commentators have imagined the Upper Guinea forests here to be primary forest, under gradually accelerating human pressure, in reality – as my own research with James Fairhead has shown – it has been a mosaic of forest, savannah and farmland for at least several centuries. The forest "islands" of Gueckedou, and parts of the larger forest reserves here and in Macenta, are actually the result of people's land use and management, having grown over enriched soils associated with settlements and farming. People in this region have long co-habited with bats, or at least bat habitats.

If something has changed to make spillover more likely, it must be in the intensity and details of people-livelihood-landscape-bat interactions, not in their basic pattern. Possible candidates might include the rapid growth of small-scale mining with its precarious forest-living conditions, or shifts in hunting practices.

A multidisciplinary approach

So, intriguing puzzles remain. Untangling these – through research that combines environmental, epidemiological, virological, veterinary and social science with local knowledge – will be key to predicting and preventing future outbreaks of Ebola, in this and other regions.
Meanwhile, the struggle to control an outbreak that is already underway in Guinea continues. May it be successful, and as soon as possible – for the sake of Guinea's own people as well as those who live beyond its borders.

By Melissa Leach, Principal Investigator of Dynamic Drivers of Disease in Africa Consortium