Connecting Global Priorities Biodiversity and Human Health

causes of disease emergence drivers may directly
and indirectly serve to protect biodiversity (Karesh
et al. 2012).
Moreover, given that health and land management
decisions are rarely made on the basis of a single
pathogen, we need to move towards a multiple
pathogen approach and increase our focus on
pathogens of major human health relevance. By
closing these gaps we will improve our ability
to identify synergies between biodiversity
and net human infectious disease risk burden
where they exist, and move to a predictive,
impact-based framework. While EIAs may be
commonly employed for potential environmentmodifying
projects, also applying health impact
Box 3: Sentinel surveillance opportunities for the prevention of Ebola outbreaks
The long-running and highly disruptive human Ebola outbreak in West Africa (responsible for >25
000 reported human cases between December 2013 and early April 2015) demonstrates the
public health challenge posed by the Ebola virus. Despite global attention and response, over
fteen months into the outbreak the initial source of the outbreak had still not been denitively
identied (WHO 2015). While the number of new cases had shown signs of decline as of early
April 2015, intense transmission was continuing in parts of Guinea and Sierra Leone. Prior Ebola
outbreaks in humans, and a concurrent outbreak in the Democratic Republic of Congo beginning
in August 2014, have been linked to the hunting or handling of wild animals, with subsequent
human–human transmission (Rouquet et al. 2005; Feldmann and Geisbert 2011). Some bat species
are the suspected natural reservoir for the virus and are thought to harbour it without symptoms.
Investigations of wild animal carcasses have detected infection and mortality in chimpanzees, gorillas
and duikers, suggesting that they may serve as intermediate hosts for potential human spill-over
(Rouquet et al. 2005). Ebola virus has also been recognized as causing severe declines in great ape
populations, especially critically endangered wild lowland gorilla troops (Leroy et al. 2004; Olson et
al. 2012).
Ebola virus outbreaks in humans are typically sporadic, presenting a challenge for ongoing detection
and monitoring (Leroy et al. 2004). Data generated from the Animal Mortality Monitoring Network
in Gabon and Republic of Congo and subsequently the United States Agency for International
Development (USAID) Emerging Pandemic Threats PREDICT programme suggest that surveillance for
Ebola virus circulating in wildlife may enable early detection or prevention of Ebola virus outbreaks
in humans (Rouquet et al. 2004; Olson et al. 2012). Finding fresh wild animal carcasses had been
viewed as a food resource and a sign of good fortune for some hunting communities, but poses risks
for human transmission (Karesh and Cook 2005). To manage and reduce risks from Ebola virus spillover,
reporting of deceased or sick animal sightings by hunters and foresters can provide important
sentinel benets for public health and conservation monitoring, informing opportunistic sampling
by trained eld teams who can respond to reported morbidities and mortalities in wildlife with
sampling and testing eorts (Rouquet et al. 2005; Olson et al. 2012). Additionally, non-invasive
great ape faecal sampling may provide a cost-eective surveillance method and provide data on
Ebola virus exposures and survival to benet conservation strategies (Reed et al. 2014). This One
Health approach, paired with sharing of information on Ebola virus detection across health and
wildlife authorities and local hunting communities, allows for targeted early detection eorts and
implementation of preventive measures.
146 Connecting Global Priorities: Biodiversity and Human Health