The answer is body's line of defense. The first line of defense which includes physical as well as chemical barriers would defend the body from infection. It would include the tears, cilia, stomach acid,urine, white blood cells,mucus and the skin. The skin is the largest organ and would act as a barrier from pathogens. If first line of defense won't work the second line will then be activated.
It is a tick disease so whenever the ticks are out people can get it. If you live in Northeastern United States these fall in Fall and Winter season when most people and animals get bitten.
