Predominantly in the upper Midwest and Northeast of the United States as well as in parts of Europe, when caught early, Lyme disease is usually easy to treat. But, if missed, this tick-borne infection can cause significant cardiac, neurological, cognitive and other health problems.

Charles Wolgemuth, an associate professor in the UA Departments of Physics, and Molecular and Cellular Biology along with a graduate student- Dhruv Vig, came up with a mathematical model that could help detect the bacteria's spread in the early stages of the disease.

"It actually started off as a class project here at the UA... we did a very preliminary, early stage version of the model just looking at the bacteria interacting with Macrophages, your immune cells, and that it actually changes over time," Vig said. "After the class was over, then we said, can we expand that out and actually look at how does the rash evolve over time."

The model, researchers said, describes bacteria's location in relationship to the rash, and their interaction with the immune system while they are in your skin. The model also reveals that in cases when patients develop a bull’s eye rash, immune response, being strongest at the center of it, clears most. But as time progresses the bacteria continue to spread outward and also rise back again at the center.

"One of the interesting things we found is that the rash appearance does not necessarily indicate how well or not well the antibiotics are working," Wolgemuth said. "So you could take antibiotics and end up still having a rash, but all your bacteria have been cleared from your kind of lets you know, that the typical treatments that have been given are actually...viable."

This model, if advanced, may also answer to what happens when bacteria get into blood and other tissues, and how antibiotics can affect concentration of the numbers of bacteria in a body over time.

The researchers, by using the model, aim to go beyond studying just Lyme disease.

One of the advantages of modeling is its replication and application to other infectious diseases that causes skin rashes, Vig said. Using some sort of the same set up and thought process, we can tackle it onto other diseases, he explained.