Dynamic Drivers of Disease in Africa

The Dynamic Drivers of Disease in Africa was an ESPA (Ecosystem Services for Poverty Alleviation) funded research programme designed to deliver much-needed, cutting-edge science on the relationships between ecosystems, zoonoses, health and wellbeing, with the objective of helping people move out of poverty and promoting social justice. The project investigated whether disease regulation as an ecosystem service is affected by changes in biodiversity, climate and land use, with differential impacts on people’s health and well-being.

The Dynamic DDDAC comprised 21 partners spanning Africa, Europe and the US, and included researchers from the environmental, biological, social, political, and human and animal health sciences. It was an integrated multidisciplinary – or One Health – approach to understanding animal-to-human (zoonotic) disease transmission. A main objective was to generate evidence and advance understandings of the complex relationships between zoonoses, ecosystems and wellbeing to inform effective poverty and public health interventions.

The key questions the study sought to explore were:

• What kinds of ecological changes (in, for example, biodiversity, vegetation and habitat, and water) are affecting possible animal-to-human disease spillover?
• What uses of ecosystems by different people bring them into contact with possible disease risk?
• How are these local dynamics affected by wider changes, such as those in climate, land use and urbanisation?
• How do different people and agencies understand and represent these dynamics and what are the implications for public health policy?

Research focused on four emerging or re-emerging zoonotic diseases in four diverse African ecosystems, with an innovative, holistic approach marrying the natural and social sciences to build an evidence base designed to inform global and national policy players seeking effective, integrated approaches to control and check disease outbreaks.

The Ghana case-study focused on Henippaviruses (Hendra and Nipah Virus) which are known to cause encephalitic disease in people, with high fatality rates.

 

The viruses’ natural reservoir hosts are pteropid fruit bats (flying foxes) found in Australia and Asia. However, the viruses have been identified to be maintained within the closely-related straw-coloured fruit bat (Eidolon helvum) which is widespread and abundant in mainland Africa.  Evidence of henipaviruses in human populations has not been established as yet in Ghana; however, there is evidence of henipavirus circulation in bats within the country suggesting the potential for a disease spillover from bats to humans, although no formal risk assessments have yet been carried out. The case study sought a better understanding of possible points of disease risk by exploring the prevalence and location of bats in Ghana, how people interact with bats in the context of their livelihoods and use of ecosystems, how this differed by social group and between rural and urban areas, and people’s perceptions of bats and disease.

 

Questions for the research included:

• How do different contexts of rural/urban livelihoods, poverty and ecology shape people’s interactions with bats and bat ecology?
• In what ways do these different factors shape the drivers and dynamics of henipavirus infection within the bat population?
• Do this result in different likelihoods of spillover and who is most at risk?
• Are there high-risk groups for henipavirus exposure based on people’s use of ecosystem services, as differentiated by factors such as gender, age, social status and wealth?
• Is spillover of henipavirus occurring? If so, how do spillover dynamics and henipavirus transmission differ between urban and rural sites, and why, taking into account changes in biodiversity and land use.
• Have land-use changes pushed bats to feed in urban and orchard areas, where contact rates and risk of human exposure are higher?

Visit www.driversofdisease.org  to read more about the project. 

Funding partners: Ecosystem Services for Poverty Alleviation (ESPA)

Starting Date: 2012

Ending Date: 2016

Work Packages: Ecosystem Services

Location: National