Lyme disease is on the rise, and researchers are working to learn more about how it’s transmitted. Tick bites are known to cause the illness, but a bacterium that resides in a mouse is to blame; the ticks become infected with the bacterial pathogen after biting the mice. Now scientists have sequenced the genome of that mouse, the white-footed rodent called Peromyscus leucopus. They live in shrubbery, wetlands, and forests, unlike common house mice. This work, which took four years to complete and may help stop the transmission of Lyme disease, has been reported in Science Advances.
“Many efforts to combat Lyme disease have focused on trying to control those ticks, but they have been difficult to put in practice. So we decided that instead we should look at the animal carrying it,” explained Lyme disease pioneer Alan Barbour, M.D., a professor of medicine and microbiology & molecular genetics at the University of California, Irvine School of Medicine.
Around 1981, the bacterium Borreliella burgdorferi was identified as the causative agent behind Lyme disease, which was first described at a scientific meeting in 1909.
From 2016 to 2017, Lyme disease diagnoses rose around 17 percent, from 36,429 to 42,743 cases, according to the Centers for Disease Control and Prevention (CDC). Since the late 90s, cases have tripled. The changing climate, forest growth in fields previously used for agriculture, and suburban development near these wildlife interfaces are all thought to be contributing to the rise in cases.
Barbour and his research collaborators began to investigate how the mouse is involved in the spread of the disease, and looked to genetic data for answers. Their efforts revealed that the white-faced mouse has more in common genetically with hamsters than house mice. The data is also now freely accessible to other researchers.
“If you want to understand a species, knowing its genetic blueprint is invaluable,” said Anthony Long, Ph.D., a professor of ecology & evolutionary biology in the UCI School of Biological Sciences. “It provides a road map that makes new research approaches much faster and more efficient.”
Now the scientists can begin to look for ways to stop Lyme from being transmitted. They may be able to create a vaccine that can be deployed on white-footed mice in the wild. It may sound strange at first, but rabies is already prevented this way. The rodents also don’t feel the negative impacts of the bacterium. They may help us find a way to stop the disorder from progressing.
“Understanding what shields them from getting sick could guide us in protecting humans from it,” Barbour added. These rodents are also vectors for emerging infections that are similar to malaria and Rocky Mountain spotted fever.
Prevention is still critical to stopping the spread of Lyme, which can be a serious illness. Learn more about Lyme disease from the videos.
Sources: UCI, Science Advances