Weather Forecast


Cases of tick-borne diseases decreased in 2012

An unusually warm, dry spring and summer may have contributed to a substantial drop in cases of disease caused by ticks in 2012 in Minnesota.

However, the decline doesn't mean the risk of illness from tick bites in 2013 will be any less than in most previous years, state health officials reported.

The three main tick-borne diseases carried in Minnesota by blacklegged ticks (deer ticks), Lyme disease, human anaplasmosis and babesiosis, were all down in 2012.

There were 911 confirmed cases of Lyme disease, down from 1,201 in 2011 and the lowest since 2003. There were 503 cases of human anaplasmosis in 2012, down from 782 in 2011 and 40 cases of babesiosis in 2012, down from 72 in 2011.

Despite an early warm-up in spring that led to an earlier than normal start to tick activity, continued hot, dry weather may have reduced blacklegged tick feeding activity, thus lowering disease risk, said David Neitzel, tick-borne disease specialist with the Minnesota Department of Health (MDH).

Neitzel expects the highest risk period for tick-borne diseases to occur over the next few weeks in Minnesota.

Besides the three commonly reported diseases, blacklegged ticks carry the agents for Powassan disease and a new form of human ehrlichiosis. American dog ticks (wood ticks), which are common in spring and early summer throughout Minnesota, can carry Rocky Mountain spotted fever (RMSF).

The best way to prevent tick bites is to avoid tick habitat during warm weather months: wooded or brushy areas for the blacklegged tick and grassy or wooded areas for the American dog tick.

If you can't avoid tick habitat, use repellent, such as DEET-based or permethrin-based repellent, to reduce the risk of disease.

Early detection of tick-borne illness is important to prevent potentially severe complications. Signs and symptoms of the various tick-borne diseases can include, but are not limited to, rash, fever, headache, fatigue, muscle aches, and joint pain or swelling.

These symptoms can be associated with other diseases, so it is important for patients to mention possible tick exposures or time spent in tick habitat to their medical provider.

Except for Powassan disease, which is caused by a virus, all of Minnesota's tick-borne diseases are treatable with antibiotics.

More information about Minnesota's tick-borne diseases, including signs, symptoms, and prevention, is available at or by calling MDH at (651) 201-5414.