Reports of Lyme Disease cases in the United States have increased over the last 2 decades. Lyme Disease is the most prevalent tick borne disease of humans in the US. In infected people, Lyme disease invades tissues of the body. The pathogen itself is not present in blood, making it difficult to detect. Tests for Lyme Disease markers have improved and better diagnosis may be one reason behind the “expansion”. However, studies of both tick abundance and disease incidence suggests that the tick vector, Ixodes scapularis, is expanding its geographical range and increase in Lyme cases is correlated with geographic expansion of the tick into new areas.
In the upper Midwest, Lyme has historically been prevalent in Wisconsin and Minnesota. A multi year study* has documented an expansion of both the tick and Lyme Disease in Michigan. In many regions, conditions are ripe for large tick populations due to a increase in wild rodent hosts of the ticks. Those who visit the woods this summer should consider the use of a tick repellent. With Lyme disease, an ounce of prevention is worth a pound of cure.
*Paul M. Lantos Jean Tsao Lise E. Nigrovic Paul G. Auwaerter Vance G. Fowler Felicia Ruffin Erik Foster & Graham Hickling. Geographic Expansion of Lyme Disease in Michigan, 2000–2014. Open Forum Infect Dis (2017) 4 (1): ofw269.