Human impact on parasitic disease questioned
Human behaviour could be a major contributing factor in the transmission of parasitic infections to wildlife, research being conducted across WA suggests.
A recent review has critically reconsidered the significance of a concept called the 'One Health Triad' which looks at disease interactions between humans, domestic animals, wildlife and the environment.
Murdoch University School of Veterinary and Health Science's Andrew Thompson says this research challenges the idea that the flow of parasitic diseases from animals to humans is one-way.
"The impetus for the development of this so-called one health concept was principally thinking about diseases wildlife were giving to humans and domestic animals," Professor Thompson says.
"We need to not just consider wildlife as the villains, because ultimately we are just as much the villains as wildlife are."
He says urban expansion, mining exploration, animal transportation and captive breeding programs are all potential causes of increased susceptibility to disease that have been previously unexplored.
"We don't know, it's a very interesting phenomenon," he says.
"The problem is that these animals are being exposed to novel domestic parasites that they may, and are, suffering quite seriously from."
He says a lack of adequate surveillance presents a major challenge to the documentation of pathogen diversity and prevalence among native Australian fauna.
The impact of human behaviour on an animal's ability to cope with parasitic infection is still largely unknown due to this lack of data.
"[We think] many of these diseases are common as an infection, but they are not that common in wildlife as a disease," he says.
"If you stress the animal ... it's far more likely to suffer the consequences [of that infection].
"Then again we have other diseases that we've inadvertently allowed wildlife to have access too."
He says the decline of the now critically endangered woylie (Bettongia penicillata) is one example where not enough is known, but human impact is likely.
"That decline is associated with a parasitic infection they've probably had for thousands of years," he says.
"But there are certain circumstances making the woylie more susceptible to the clinical consequences of those infections."
He says the introduction of a genetically very similar, but foreign, parasite brought in by humans or environmental stresses caused by habitat decline could be facilitating the woylie's susceptibility to parasitic infection.
Through an Australian Research Council grant, research will now focus on trying to identify human behaviours that are having the biggest impact on native fauna's susceptibility to parasitic disease.