MISSOULA – Since hantavirus cardiopulmonary syndrome was first named in 1993, more than 700 people have become infected and more than 250 have died from it in the United States. The devastating disease, caused by Sin Nombre hantavirus, is spread primarily by and among deer mice.
In August, University of Montana Assistant Professor Angela Luis received a $200,000 grant from the National Science Foundation to study how competition with other rodent species affects the spread of hantavirus among deer mice.
Disease ecologists fervently debate whether biodiversity loss leads to an increase in disease transmission. In a July paper published in the Proceedings of the National Academy of Sciences, Luis showed that species diversity can have both positive and negative influences in disease transmission in the same system.
Hantavirus tends to be less prevalent in diverse rodent communities, since multiple species in a system results in fewer individual deer mice and slows down the spread of infection. But the virus passes more easily between deer mice in those same populations because competition with other species either changes the rate individual deer mice encounter one another or stresses them out and lowers their immunity.
Using funding from the NSF grant, Luis and her team will examine just how competition among rodents influences these factors, specifically measuring how the presence of voles affects contact rates between deer mice, their stress levels and immunity. The results could provide insights into disease transmission dynamics in other species.
Andreas Eleftheriou, a doctoral candidate in UM’s W.A. Franke College of Forestry and Conservation, will lead experiments on the college’s Bandy Ranch, located northwest of Ovando, where he will set up 30-meter-by-30-meter pens stocked with varying numbers of voles and deer mice.
To measure contact rate, Eleftheriou will dust individual mice with fluorescent powder, which will brush off onto other rodents they come into contact with. Researchers also will collect blood and fecal samples to measure stress levels and immunity.
“We’re excited to get started with these experiments at the Bandy Ranch,” Eleftheriou said. “By conducting controlled experiments in an outdoor setting, we will be able to tease apart mechanisms that drive the spread of hantavirus in deer mice when competition with other rodents is present.”
Emily Weidner, a FCFC master’s student, also will examine how broader species diversity affects deer mice numbers and disease transmission by analyzing 20 years of data tracking hantavirus prevalence across more than 20 field sites in Montana, Colorado, New Mexico and Arizona.