Climate Change Increases Infectious Disease Prevalence

Two zoologists claimed that the emergence of infectious diseases, such as the West Nile Virus and Ebola, in unconventional locations is sparked by climate change.

"It's not that there's going to be one 'Andromeda Strain' that will wipe everybody out on the planet," Daniel Brooks, of the Harold W. Manter Laboratory of Parasitology at University of Nebraska-Lincoln (UNL) said in a news release. "There are going to be a lot of localized outbreaks putting pressure on medical and veterinary health systems. It will be the death of a thousand cuts."

Brooks and Eric Hoberg, of the United States Department of Agriculture (USDA)’s division of Animal Parasitic Diseases, outlined this concern in a special Feb. 16 issue of the Philosophical Transactions of the Royal Society B.

Through observation, Brooks and Hoeberg — Brooks who observed tropical parasites, and Hoeberg who researched in the Arctic — saw the extinction and introduction of species, and in turn parasites both adopting new hosts and moving locations.

"Over the last 30 years, the places we've been working have been heavily impacted by climate change," Brooks commented in an interview. "Even though I was in the tropics and he was in the Arctic, we could see something was happening. Changes in habitat mean animals are exposed to new parasites and pathogens.”

Brooks also claimed West Nile Virus is a prime example of this phenomenon, going from an acute problem in North America and escalating into a chronic one.

As a result, the investigators urged for scholars to consider that pathogens retain genetic aspects which enable them to adopt new hosts. Brooks said this is the mechanism that allows many infectious diseases to spread to new locations despite lacking a common host — a claim that goes against more than 100 years of evidence suggesting that parasites don’t quickly change hosts.

Moreover, Brooks and Hoberg urged that grasping how host-parasite interactions are started, perpetuated, and prevented is essential for controlling many environmental and ecological issues, including emergent infectious diseases (EIDs) and climate change itself.

Concluding their study, they determined since climate change and emerging diseases cannot be automatically stopped, risk management is more effective and less cost-associated than responding to crises.

“The species most successful at surviving global climate changes will be the primary sources of EID, so host extinction will not limit the risk of EID,” the authors wrote. “The planet is thus an evolutionary and ecological minefield of EID through which millions of people, their crops and their livestock wander daily.”