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Tapeworm infection is caused by ingesting food or water contaminated with tapeworm eggs or larvae. Credit: University of Alberta |
A new study looking at research on parasitic worms suggests the pesky but pervasive creatures have a far greater impact on the health of mammal populations than previously known.
“Parasites don't have to kill the animal to control a population,” says Kyle Shanebeck, a PhD student in the Faculty of Science’s Department of Biological Sciences who led the research review.
Shanebeck’s analysis shows that helminths — large parasites such as tapeworms, flatworms and flukes — have negative effects on the energetic condition, or total body health, of their mammal hosts that can impair systemic functioning, repair, growth, environmental adaptability and reproduction.
“They can affect the animal’s ability to absorb nutrients, which can affect digestive health and behavior, making them more aggressive and even changing where they forage,” notes Shanebeck, whose research is supervised by assistant professor Stephanie Green. “Helminth parasites also suppress immune action or weaken it, as the body spends energy to mount an immune response to fight them which can make a secondary infection worse.”
As Shanebeck explains, assessing population health in wildlife typically focuses on pathogenic diseases — the often-fatal illnesses that can spread between species, and potentially from animals to humans. Parasites, on the other hand, don’t kill their hosts so they tend to be ignored in conservation and management models.