Roughly 60% of emerging infectious diseases worldwide start in animals, according to the World Health Organization, and about three-quarters of the new human pathogens identified over the past 30 years came from animal populations. At Montana Technological University, one researcher has spent nearly three decades building the data needed to understand how those threats emerge, one deer mouse at a time.
A Career Born in an Outbreak
Dr. Amy Kuenzi, head of Montana Tech’s Department of Biological Sciences, was a doctoral student at the University of Arizona in 1993 when a mysterious respiratory illness hit the Four Corners region. Scientists traced it to Sin Nombre hantavirus, carried by deer mice. By the end of that year, the CDC had recorded 53 cases and 32 deaths, a fatality rate of 60%.
Kuenzi’s advisor received emergency CDC funding to screen small mammals for the virus, and Kuenzi joined the effort. Today she maintains Montana’s longest-running dataset on hantavirus prevalence in deer mice. As she explains it, long-term studies are the only way to truly understand disease dynamics in wildlife populations, and years of accumulated data let researchers ask new questions long after the samples were collected.
What the Fieldwork Looks Like
Kuenzi and her students set grids of baited live traps at study sites across Montana in the late afternoon and check them early the next morning. Because hantavirus spreads through aerosolized particles from rodent urine, feces, and saliva, the team wears gloves and fitted respirators and disinfects equipment throughout. Each mouse is ear-tagged, weighed, measured, and blood-sampled before being released.
Samples go onto dry ice in the field and into long-term freezer storage. In the lab, students test for antibodies, extract DNA, and screen for pathogens. Archived samples are often revisited years later with newer techniques. Kuenzi noted that a recent population spike in mice coincided with a spike in hantavirus prevalence, which made for physically demanding summers in the field.
New Discovery: Bartonella in Montana Rodents
The archive is now paying off in a new direction. Working with Dr. Katie Hailer, Kuenzi’s team has screened stored blood samples for Bartonella, the bacterial genus behind cat scratch disease and trench fever. No one had previously looked for Bartonella in Montana rodents, and the team found it at most sites. A student will sequence the DNA this summer to identify the species involved, another first for the state.
Predicting the Next Spike
Kuenzi also collaborates with disease ecologist and modeler Dr. Angela Luis and Ph.D. students at the University of Montana. The team combines weather data, population trends, and infection rates to model how environmental conditions drive disease prevalence, with the goal of predicting future infection spikes rather than only explaining past ones.
In a 2023 paper in Royal Society Open Science, Kuenzi and Luis showed that food availability shapes social contact among deer mice. They concluded that practical steps like rodent-proofing and proper food storage could help prevent spillover to humans, not only for Sin Nombre hantavirus but for rodent-borne pathogens worldwide.
Why It Matters for Veterinary Professionals
This work is One Health in practice. Long-term wildlife surveillance gives clinicians, public health veterinarians, and researchers the baseline data needed to spot emerging threats early. The project has also become a pipeline for future health professionals: Kuenzi says former students have gone on to veterinary school, medical school, dental and PA programs, and research careers.
As Kuenzi puts it, decades of trapping mice may seem unusual, but the animals reveal a great deal about disease dynamics and how the environment shapes them.
Read the Original Story
Montana Technological University, “Tracking tomorrow’s threats: Montana Tech researchers study the future of zoonotic diseases,” October 2026.