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Lyme Disease: Data and Statistics

In 2017, 143 cases of Lyme disease were reported in Indiana, for an incidence rate of 2.14 cases per 100,000 population. For the five-year reporting period from 2013 to 2017, 660 cases of Lyme disease were reported (Figure 1). While the disease is most common in the spring and summer months when ticks are active, Lyme disease can occur anytime during the year (Figure 2). Lyme disease can occur in all areas of Indiana, but most cases occur in the northwest part of the state. People who live in or travel to this part of the state are at increased risk for developing Lyme disease. Figure 3 depicts cases of Lyme disease by county of residence. Figure 4 depicts cases of Lyme disease by the county of likely exposure as determined by public health investigation. This does not include people who reported an unknown county of likely exposure or likely exposure in other states.

For Lyme disease tick infection maps, click here.

Figure 1. Lyme Disease Cases by Year — Indiana, 2013–2017

Figure 2. Lyme Disease Cases by Month of Illness Onset – Indiana, 2017

 Figure 3. Lyme Disease Case Counts by County of Residence – Indiana, 2017


Figure 4. Lyme Disease Case Counts by County of Likely Exposure – Indiana, 2017

NOTE: These data include confirmed and probable cases according to national surveillance case definitions adopted by the Council of State and Territorial Epidemiologists (CSTE). The Lyme disease case definition may be found at https://wwwn.cdc.gov/nndss/conditions/lyme-disease/case-definition/2017/ . All rates are calculated per 100,000 population based on the U.S. Census Bureau’s population estimates as of July 1, 2017, obtained on July 10, 2018.

For prior years’ Lyme disease statistics, please visit our annual report pages.


Page Last Updated: March 29, 2019

Page Last Reviewed: September 4, 2018