Dr. Christian Lange has spent over 15 years researching viruses, and his new study on Ebola is shedding light on how colonial land use has helped viruses spread and evolve.
Dr. Christian Lange
"We have actual historic data that identifies the likely events that drove the emergence of Ebola," says Lange, who teaches biology in the Faculty of Science at Kwantlen Polytechnic University (KPU). "Previously, it was unclear why this virus came out of the forest, but we were able to track a colonial scheme that exactly coincides with the time and the place where we think the virus originated."
Lange's research took him to Central Africa, where the most recent common ancestor of the Ebola Zaire virus was found to be circulating in the forests of the Democratic Republic of the Congo (DRC) around 1960. In the two decades prior, the landscape underwent significant fragmentation driven by the Belgian Congo government to support cash crop agriculture. Simultaneously, the South Sudanese savanna underwent a massive transformation under British rule prior to the emergence of Ebola Sudan.
"In the DRC, it wasn't necessarily a transformation from forest to farmland that disrupted things it's more subtle. Even if you build one narrow road, you can displace species in the area that may avoid this new barrier. If we look at the data, it's these subtle changes that actually have the bigger effects."
Lange's study shows that these disturbances are associated with the divergence and dispersal of new variants of Ebola into new ecoregions across Africa. Currently, there are six known species within the genus Ebolavirus, and four of them - including Ebola Zaire - cause a severe and often fatal hemorrhagic fever in humans and other mammals.
Between 2014 and 2016, an Ebola epidemic resulted in at least 28,000 suspected cases and over 11,000 deaths. Since then, Lange has observed a worrying trend.
"Overall, the pattern is that we are seeing more Ebola than before," he explains. "The first Ebola cases were in 1976, but there were relatively few until about 2000. Now, there are outbreaks almost every year, mostly in the DRC."
A large proportion of human pathogenic viruses is zoonotic transmitted from animals to humans. In the past, domestic animals have been responsible for these transmissions, but now Lange is more concerned about wildlife. Since other related viruses come from bats, that was the logical starting point for his research.
"Bats are extremely diverse. They are the second-largest group of mammals. In Canada, there are less than 20 bat species. In Africa, there are hundreds. There are probably multiple species of bats that have their own Ebola viruses. At one point, people got in contact with these bats," says Lange.
Although people hunt bats in some parts of Africa, Lange believes the main issue is that people disturbed the bats by changing their habitats. Out of necessity, the bats migrated and interacted with other bat species.
"Whenever a virus is exposed to new conditions or transmitted to a new species, it evolves and adapts."
If current rates of deforestation and fragmentation remain, Lange warns that we can expect the zoonotic event trend of the last decade to continue.
Bolstering resources for education and scientific research in developing nations, along with introducing medical system reforms, could help mitigate the effects of the spread, Lange suggests.
"The Congo has some excellent scientists, but they don't have a lot of resources to do research. To develop a vaccine, or to prevent spillovers, we need to know what we're fighting. Otherwise, it will take a lot longer to develop a solution."
Lange anticipates that his study will lead to further research, but he also hopes to reach the conscience of the public.
"People should consider the impact of land use. Any interference with pristine habitats no matter how small has an effect, and in some cases will cause zoonotic events with unpredictable outcomes."
KPU's Faculty of Science offers traditional and applied undergraduate opportunities, including Bachelor of Science programs in Biology and Health Science.
