Reported Lyme Disease Cases in the U.S. by County

The Lyme Disease Association Inc. is providing you with information from the Centers for Disease Control & Prevention (CDC) on the U.S reported Lyme disease case numbers by county in each state for the years 2000-2018.

  • 2000-2007 data reflect surveillance case definition at that time and reflect confirmed cases.
  • 2008-present data reflect that surveillance case definition which allows for reporting of confirmed & probable cases.
  • County codes of 999 represent unknown county of residence in each state.
  • Annual cases are generally published in the fall of the following year.
  • CDC has indicated Lyme Disease is under-reported by a factor of 10.

Click here for Excel Document – U.S. Lyme Disease Case Counts by County 2000- 2018