Sunday, October 19, 2014

The link between environmental degradation and Ebola

Peter Stoett and Catherine Machalaba in the Toronto Star:  The Ebola epidemic besieging West Africa is perhaps the starkest warning yet that as we tear down forests, we open ourselves up to new strains of virulent disease. Among the key lessons from the current outbreak is that human-created pressures such as intensified food production, rapid trade and travel, and climate change, are putting future generations at risk of further Ebola-like catastrophes.

Through some mix of travel control, medical advances, and humanitarian assistance, we can hopefully stop the current outbreak’s carnage. But what can we do to prevent future outbreaks of so-called exotic diseases?

Delegates at the recent UN conference on biodiversity in South Korea expressed particular concern that the long-term alteration of habitats (by, for example, logging, farming, mining) and speeding climate change will increase the chances of the spread of exotic diseases. They compellingly made the case that Guinea, Liberia, and Sierra Leone are all known for their high deforestation rates; and each has been affected by periods of civil strife that exacerbated population displacement and relocation.

It would be premature to conclude that deforestation or other causes of ecosystem change were the factors behind this outbreak, but they remain part of the equation for Ebola, other emerging illnesses and even established diseases like malaria.

Unsustainable policies designed to increase agricultural output for export, illegal logging, the mercurial rise of the palm oil industry and the hunt for oil and gold within tropical and boreal forests — all of these place humans in greater contact with wild species, in some cases for the first time, enabling more efficient transmission of diseases both known and unknown.

Indeed, scientists started linking infectious diseases with environmental alteration decades ago. Today, climate change complicates the issue: most predictions (many of them already realized) suggest the changing climate will allow for the spread of invasive species, degrade ecosystems’ resiliency and ultimately broaden the reach of some diseases....

CDC Disease detective Kari Yacisin (left) conducts contact tracing for Ebola in West Africa with a local health official. CDC photo via Wikimedia Commons, under the Creative Commons 2.0 license

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