Tickborne Diseases and Conditions

In Minnesota, there are about a dozen different types of ticks. Not all of them spread disease but it is always best to protect yourself against tick bites. The most common ticks that people come across in Minnesota are the American dog tick (commonly known as the wood tick) and the blacklegged tick (commonly known as the deer tick). The blacklegged tick causes the most tickborne diseases in Minnesota.

Diseases Associated with Tick Bites:

• Lyme Disease
  Lyme disease, caused by Borrelia burgdorferi and Borrelia mayonii, is a potentially serious bacterial infection affecting both humans and animals. It is the most common tickborne disease reported in Minnesota and in the United States. The incidence of Lyme disease in Minnesota has been increasing in recent years.
• Anaplasmosis
  Anaplasmosis, formerly known as human granulocytic ehrlichiosis (HGE) is a bacterial disease that was first recognized in Minnesota in the early 1990s. It is transmitted to people by blacklegged ticks (deer ticks), the same ticks that transmit Lyme disease.
• Babesiosis
  Babesiosis is a protozoan infection that occurs infrequently in Minnesota. It is also transmitted to people by blacklegged ticks (deer ticks), but it less common than both Lyme disease and anaplasmosis.
• Ehrlichiosis
  Ehrlichiosis due to Ehrlichia muris eauclairensis is transmitted to people by blacklegged ticks (deer ticks) and was first reported in 2009. Cases have only been identified in Minnesota and Wisconsin. Ehrlichiosis caused by Ehrlichia chaffeensis is found throughout much of south-eastern and south-central United States and is transmitted by the lone star tick. It is not a common disease in Minnesota, although a small number of cases have been reported. 
• Powassan Virus Disease
  Powassan virus is a tickborne flavivirus that has been reported in patients from the Upper Midwest and Northeastern states. It was first reported in a Minnesota resident in 2008 with cases reported almost every year since then.
• Hard Tick Relapsing Fever (HRTF)
  Hard tick relapsing fever (HRTF) is caused by Borrelia miyamotoi and is transmitted to people by blacklegged ticks (deer ticks). It is distantly related to the bacteria that cause Lyme disease. Small numbers of human cases have been reported to date from the Upper Midwest and Northeastern states.
• Borrelia mayonii (Lyme Disease)
  Borrelia mayonii was first identified in 2013 and found to cause an illness similar to Lyme disease. In 2016, scientists determined that the illness caused by this bacteria can also be classified as Lyme disease. 
• Rocky Mountain Spotted Fever (RMSF)
  Rocky Mountain spotted fever is extremely rare in Minnesota, but isolated cases have been reported within the state. This disease is transmitted by the American dog tick.
• Tularemia
  Tularemia is a potentially serious illness that occurs naturally in the United States. It is caused by the bacterium Francisella tularensis and can be transmitted by American dog ticks as well biting flies or infected animals. Human cases of tularemia are rarely reported in Minnesota.

Conditions Associated with Tick Bites:

• Alpha-gal Syndrome (Red Meat Allergy)
  Alpha-gal syndrome (AGS), is an allergic condition that can occur after a tick bite. In the United States, AGS is primarily associated with lone star ticks which are rarely found in Minnesota.

Tickborne Diseases Affecting Travelers

Minnesota residents who travel to other countries or certain areas of the United States may become sick with one of the tickborne diseases listed above or other tickborne diseases. Avoidance of tick bites and use of tick repellent are recommended when traveling to potential tick habitat within affected areas. For more information on international travel, visit International Travel & Infectious Disease.

• CDC: Diseases Transmitted by Ticks
  A Lists of known pathogens spread by ticks.