Researcher Asks Where and When the Next Disease Outbreak Could Happen

It was one of those things you hear about on the news: an outbreak of monkeypox in the Chicago area. An animal dealer placed infected rats from Africa next to a crate of prairie dogs. The disease spread to the prairie dogs, which were then sold in pet stores across the nation. Dozens of people in multiple states were sickened from contact with the animals.

The incident gave Kansas State University veterinary medicine graduate Christine Ellis a little bit of global perspective. At the time, she was working as an associate veterinarian at the Midwest Bird and Exotic Animal Hospital in the Chicago area.

"It really made me realize how fast disease can spread -- and how easily," she said.

It also motivated her to want to do more to protect public health. After all, the veterinarian's oath covers both animal and public health.

So after a three-year research fellowship at the Centers for Disease Control studying viruses like West Nile and Japanese encephalitis, she returned to her alma mater to find ways to predict where and when a disease might crop up.

Ellis, who entered K-State's master's of public health program in the spring, is working in a new field called spatial epidemiology. It is the geographic study of where disease occurs and how the environmental conditions at the time contributed to the disease's spread and proliferation.

Ellis takes individual cases of monkey pox in the Congolese Basin, charts their exact longitude and latitude, and spends hours researching the exact environmental conditions at the time. Those environmental factors include moisture, seasonal variation, vegetation and temperature. She even looks at the wildlife in the area.

"It's like playing Sherlock Holmes," she said. "You work backward and try to figure out where the disease came from and pick apart the ecology of the disease. Then you use that information to map where those same conditions exist across the globe."

Ellis plugs each of the data points into a specialized software program that places them on a geographic map. The program then looks for places with similar conditions.

Though spatial epidemiology is a relatively new discipline, it's proven to be pretty accurate. Her thesis adviser, Townsend Peterson from the University of Kansas, used this method to predict how the West Nile virus might spread before it emerged in the U.S.

"Turns out, he was about 80 percent right," Ellis said.

Being able to predict where and when disease could crop up has immense value for disease surveillance in an increasingly global society. Ellis ought to know -- she also teaches epidemiology.

"Knowing where the most favorable conditions for a disease exist will be an invaluable tool to lay out prevention and treatment strategies ahead of time," she said.

Lisa Freeman, associate dean of research and graduate programs for K-State's College of Veterinary Medicine, said that the public benefit of research like Ellis' is exactly why K-State started the master's degree in public health in 2003.

"Dr. Ellis has made significant contributions to the college and university through our teaching program and her research focus in niche modeling," she said. "Her work will add to both the academic and real-world understanding of emerging diseases."

Once Ellis is done discovering the likely places monkeypox could survive, she'll move on to the plague. She has decades of data laying out the history of plague in the U.S., including specifics about the people and animals infected, and the types of fleas involved.


"We can look at the distribution of the animal hosts and the fleas," she said. "Or we can analyze the animal data and the flea data, then overlay those onto the human data to look for spatial trends in disease occurrence from the environmental, temporal and spatial perspectives."

In Ellis' eyes, the possibilities are endless.

"This data could enable us to predict where disease might occur or may be occurring," she said. "The value to public health is immeasurable."

Source: Kansas State University