How did it come to this? It may seem that the worst Ebola outbreak ever came out of nowhere, but experts have a pretty clear idea of how it started.
Ebola infections occur through the transmission of bodily fluids, like contact with infected blood and even tears. This is why health workers and family members caring for infected individuals are at the highest risk of falling ill. But the original disease vectors are not people, they’re animals.
The currently affected region of West Africa is dense with rainforest, and monkeys and other animals, particularly bats, have been shown to harbor the virus. The unfortunate reality is that local livelihoods rely heavily on the sale and consumption of “bushmeat,” which is a catch-all term for meat from any animal from the forest. If the meat is fully cooked, then the person eating it is in no danger, but people can often expose themselves to the virus while butchering meat and preparing meals.
One plausible and troubling factor in Ebola transmission is increased human contact with animals because of deforestation. Vast portions of local forests are subject to logging, driving wildlife from their habitat and potentially increasing the risk of human infection.
The Lofa Forest borders Guinea, Sierra Leone and Liberia, and the forest is a predominant source of bushmeat to markets in all three affected countries. At present, most new infections are human to human, but chances are strong that the outbreak began with viral transmission from animal to human.
It is far more difficult to stop the initial cross-species jump, but Ebola outbreaks have been overcome in the past with successful prevention of human transmission. Local authorities and international agencies are working to contain the outbreak, but more support and supplies are needed.