Abstract
In the project proposed here, I will study the evolution of virulence of Borrelia burgdorferi s. l.; the causative agent of Lyme disease. Like many other vector-borne pathogens, the abundance of B. burgdorferi s. l. is increasing as a result of human-induced changes of the environment, for example global warming. The long-term consequences for humans and wildlife of an increased abundance of a pathogen will not only depend on the increase per se, but also on how the pathogen's virulence evolves in response to this increase in abundance. An increased abundance of a pathogen is likely to result in that more hosts are infected by two or more different strains of the pathogen simultaneously. Such multiple infections have frequently been shown to lead to competition between co-infecting strains, and one of the most fundamental predictions of current theory of virulence evolution is that competition selects for higher virulence. Thus, an increased abundance of a pathogen can also be expected to lead to the evolution of a more virulent pathogen. Here, I will address this issue with lab- and field experiments with Borrelia in rodents. An understanding of how pathogen virulence evolves could help us predict and manage virulence evolution in response to environmental change.
Sweden