Lyme Disease Statistics
From 1996 to 2012, over 17,000 cases of tick-borne diseases were reported in Minnesota, the majority of which (12,935 cases) were Lyme disease. In 2012, 912 confirmed Lyme disease cases (17.2 cases per 100,000 population) were reported. In addition, 604 probable cases (physician-diagnosed cases that did not meet clinical evidence criteria for a confirmed case but that had laboratory evidence of infection) were reported. The median number of 1,050 cases (range 911-1,293 cases) reported from 2004 through 2012 is considerably higher than the median number of cases reported annually from 1996 through 2003 (median 373 cases, range 252-866).
The number of Lyme disease cases has been increasing dramatically since the 1990s. A variety of factors, including increasing physician awareness, increasing infection rates in ticks, and expanding tick distribution may have led to this trend.
The Lyme disease cases in 2012 ranged in age from 1 to 92 years; the median age was 39 years. In 2012, 63% of Lyme disease cases were male.
Exposure to blacklegged ticks (deer ticks) and Lyme disease in Minnesota occurs primarily from May to July, and again in the autumn, when people are outdoors and ticks are actively feeding.
The majority of cases occur in June, July, and August, peaking just after the mid-May to mid-July period when the nymphal deer tick is feeding. This lag is due to the 3-30 day period between an infected tick bite and the start of signs and symptoms.
- Reported Cases of Lyme Disease in Minnesota by Year
Graph showing the number of reported Lyme disease in Minnesota by year.
- Reported Cases of Lyme Disease in Minnesota by Month of Onset
Graph showing the percent of cases of Lyme disease by month of onset.
In recent years, most Lyme disease cases in 2008 reported likely exposure to deer ticks in east-central, north-central, and southeast Minnesota.
- High Risk Areas for Tick-borne Diseases in Minnesota
A map that shows counties of highest Tick-borne risk in Minnesota.
- Lyme Disease, 2012
Minnesota Department of Health, Disease Control Newsletter;
Annual Summary of Communicable Diseases Reported to the Minnesota Department of Health, 2012.
- Lyme Disease Statistics
Maps, charts, tables, and reports from the CDC.