(Published in the Irish Times Oct 27, 2015)
A new study explores the environmental factors that give rise to outbreaks of Ebola Virus Disease (EVD). Jointly undertaken by the Environmental Foundation for Africa and the ERM Foundation it posits a connection between rainforest fragmentation and this zoonotic disease. This is hypothesised to occur through increased contact between species that normally do not come into contact with each other or with humans. These include various bat species hypothesised to play a role in the transmission of the virus to humans.
As the recent West African epidemic which began in December 2013 subsides the burning question in the region and beyond is: how do we prevent this nightmare from recurring? [A timely reminder of the effect of this terrible disease is provided by the tragic case of Scottish nurse Pauline Cafferkey who contracted the illness in the line of duty].
So far there have been over 11,000 reported mortalities with twice that number of survivors who are both physically traumatised and socially stigmatised by the disease. Moreover as of October 2014 the World Bank estimated that the economies of Guinea, Liberia and Sierra Leone could lose US $1.6 billion in economic activity during 2015.
More than this, the epidemic has generated existential fears which I encountered on a visit to Sierra Leone last May. In societies where tactile behaviour is deeply rooted prescriptions against physical contact impose uncomfortable limitations. Bans on public gatherings also distort important social rituals. Further, the increased security measures leave the potential for abuse of power.
The international community including governments and NGOs devoted considerable resources in medical assistance to prevent the spread of the epidemic. To some extent self-interest on the part of the international community was a motivation: malaria and respiratory infections continue to be far greater killers in what remain some of the world’s poorest countries. Nonetheless EVD’s terrifying symptoms that include unexplained haemorrhaging, its high mortality rate and the risk of wider contagion demanded a response.
Correctly, recovery plans for the region emphasise strengthening healthcare systems as a primary objective, but as the authors of the study point out the prevailing approach is “to treat the next outbreak as “inevitable”.” Moreover, economic recovery plans focus on a “business as usual” approach that fails to take the environmental impact of economic activities into account adequately. Thus, the regional organisation of the three state’s the Mano River Union in their post-EVD recovery plan makes no direct reference to ways of reducing the risk of future outbreaks, or for any environmental protection measures that could support this.
The study contends that: “forest loss or fragmentation, accompanied by hunting and the trade in bushmeat drive contact between humans and wild reservoirs and lead to infections.” It is not certain whether fruit bats are indeed the reservoir host of EVD that give rise to the transmission of the disease to a human being: “They may be part of a more complex chain of reservoirs and transmission chains between wild reservoirs and humans.” Forest fragmentation which changes the behaviour of bats could have repercussions elsewhere. The bats altered behaviour may be stressing other species that leads to a rare zoonotic occurrence.
The index case for the latest outbreak is believed to have been an unfortunate 2-year-old boy from Méliandou in Guinea who came into contact with an infected bat while playing in the hollow of a tree. In that region local land use is dominated by a pattern of subsistence farming commonly referred to as slash and burn agriculture.
Although mature trees are usually not a farmer’s first choice to clear, when aided by mechanization used in industrial logging or mining this task becomes a lot easier. Relatively few large blocks of forest in that region of Guinea “have not been subjected to significant, recent human manipulation” according to the authors. Indeed only a tiny proportion of the wider Upper Guinea rainforest belt remains unexploited, a process of deforestation that has accelerated considerably in recent decades. This has caused significant disturbance to bat populations creating the pre-conditions it appears for an outbreak.
The study uses time lapse satellite imagery to compare the outbreak in Guinea with others in Democratic Republic of Congo, Uganda and South Sudan. They observer similar environmental patterns of forest fragmentation that are assumed to alter the mix of wild species in a given location, including bats, affecting their stress levels and potentially reducing immunological resistance levels. The data connecting forest fragmentation with an outbreak is not definitive but the circumstantial evidence is compelling.
Based on this evidence donors should ensure that the environmental impact of economic activities including agriculture, mining and logging are assessed. People must be equipped with the skills and resources to produce food, energy and other goods without damaging their environments.
Confronting it as simply a medical issue without reference to the environmental context is insufficient. Rolling out a vaccine is important but we have no way of knowing the type or the severity of the next virus that emerges.
The authors warn against demonizing and eradicating animals that could harbour EVD. Quite apart from the morality of this, rainforests are highly complex ecosystems. Any such measures could have unintended, dire consequences. Further, the identity of the reservoir host remains unclear and seems likely to be so for some time.
The study argues that donors and the authorities in the region should incorporate natural resource management and environment impact as core evaluation criteria into their programmes “and not treat them as box ticking exercises, or consider their job done by funding an isolated, sector specific ‘forest and wild management’ project.”
Moreover, as the recent publication of the UN’s Sustainability Goals remind us, biodiversity is essential for human flourishing. The limits of natural capital must be taken into account if economic activity is to be sustainable, and that is especially important for feeding populations. The recent EVD outbreak highlights these crucial interdependencies, and the potentially catastrophic consequences of another outbreak are such that the burden is shared by us all.