Lyme disease is a potentially serious bacterial infection caused by the bite of an infected blacklegged tick (also known as the deer tick or bear tick). The disease affects both humans and animals. The Minnesota Department of Health is monitoring the spread of the disease across the state and working with residents to limit exposure to the ticks causing the disease.
The number of Lyme disease cases has been increasing dramatically since the 1990’s. A variety of factors, including increasing physician awareness, increasing infection rates in ticks, and expanding tick distribution may have led to this trend.
The majority of cases in 2014 either resided in or traveled to endemic counties in north-central, east-central, or southeast Minnesota, or Wisconsin.
People can get Lyme disease through the bite of a blacklegged tick (deer tick) that is infected with the bacteria, Borrelia burgdorferi. Not all blacklegged ticks carry these bacteria and not all people bitten by a blacklegged tick will get sick. The tick must be attached to a person for at least 24-48 hours before it can spread Lyme disease bacteria.
Blacklegged ticks live on the ground in areas that are wooded or with lots of brush. The ticks search for hosts at ground level and grab onto a person or animal as they walk by. Ticks do not jump, fly, or fall from trees.
In Minnesota, the months of May through July and September through October are the greatest risk for being bitten by a blacklegged tick. Risk peaks in June every year. Blacklegged ticks are small; adults are about the size of a sesame seed and nymphs (young ticks) are about the size of a poppy seed. Due to their small size, a person may not know they have been bitten by a tick.
All information from the Minnesota Department of Health and the CDC.