The role of individual host species and their interactions with other hosts, vectors and pathogens are more influential in determining local disease risk, the analysis found.
"Lyme disease biology in the Northeast is obviously going to differ in its ecology from Lyme disease in California," Salkeld said. "In the Northeast, they have longer winters and abundant tick hosts. In California, we have milder weather and lots of Western fence lizards (a favored tick host) that harbor ticks but do not transmit the Lyme disease bacterium."
So, these lizards should be considered unique in any study of disease risk within their habitat. Or, as Salked put it, "All animals are equal, but some animals are more equal than others."
Broadly advocating for the preservation of biodiversity and natural ecosystems to reduce disease risk is "an oversimplification of disease ecology and epidemiology," the study's authors write, adding that more effective control of "zoonotic diseases" (those transmitted from animals to humans) may require more detailed understanding of how pathogens are transmitted.
Specifically, Jones, Salkeld and Padgett recommend that researchers focus more on how disease risk relates to species characteristics and ecological mechanisms. They also urge scientists to report data on both prevalence and density of infection in host animals, and to better establish specific causal links between measures of disease risk (such as infection rates in host animals) and rates of infection in local human populations.
For their meta-analysis, the researchers were able to find only 13 published studies and three unpublished data sets examining relationships between biodiversity and animal-to-human disease risk. This kind of
|Contact: James Holland Jones|