Skip to content
TickCheck tick testing

Reports of Lyme Disease in Chester County, Pennsylvania

Browse Lyme data by state

12,697

Confirmed cases of Lyme disease in Chester County (2000 to 2020).

Ranked #1 of 67 counties in Pennsylvania. That's 9.4% of Pennsylvania's 134,624 confirmed cases.

Yearly Breakdown of Lyme Cases in Chester County

Confirmed cases reported to the CDC each year.
View as a table
Confirmed Lyme disease cases in Chester County by year
Year Confirmed cases
2000 566
2001 818
2002 818
2003 974
2004 637
2005 670
2006 481
2007 627
2008 698
2009 983
2010 637
2011 775
2012 610
2013 489
2014 200
2015 257
2016 371
2017 628
2018 678
2019 470
2020 310
2000–2020
Confirmed cases
    Chester County

    Loading the map…

    Lyme Stats for Other Pennsylvania Counties

    Confirmed Lyme disease cases by county in Pennsylvania, 2000 to 2020
    County Confirmed cases Share of state
    Chester County 12,697 9.4%
    Bucks County 9,805 7.3%
    Montgomery County 9,372 7.0%
    York County 6,454 4.8%
    Butler County 4,807 3.6%
    Berks County 4,535 3.4%
    Lancaster County 3,770 2.8%
    Delaware County 3,712 2.8%
    Lehigh County 3,399 2.5%
    Philadelphia County 3,396 2.5%
    Clearfield County 3,241 2.4%
    Westmoreland County 3,089 2.3%
    Northampton County 2,937 2.2%
    Allegheny County 2,875 2.1%
    Dauphin County 2,445 1.8%
    Cumberland County 2,159 1.6%
    Centre County 2,156 1.6%
    Jefferson County 1,953 1.5%
    Monroe County 1,910 1.4%
    Armstrong County 1,887 1.4%
    Luzerne County 1,571 1.2%
    Adams County 1,556 1.2%
    Indiana County 1,547 1.1%
    Lebanon County 1,487 1.1%
    Beaver County 1,268 0.9%
    Elk County 1,258 0.9%
    Clarion County 1,250 0.9%
    Bradford County 1,240 0.9%
    Lycoming County 1,130 0.8%
    Cambria County 1,125 0.8%
    Wayne County 1,051 0.8%
    Pike County 988 0.7%
    Lackawanna County 975 0.7%
    Bedford County 950 0.7%
    Venango County 946 0.7%
    Erie County 943 0.7%
    Franklin County 929 0.7%
    Washington County 918 0.7%
    Blair County 882 0.7%
    McKean County 838 0.6%
    Perry County 828 0.6%
    Huntingdon County 807 0.6%
    Columbia County 793 0.6%
    Susquehanna County 703 0.5%
    Carbon County 676 0.5%
    Wyoming County 634 0.5%
    Mifflin County 621 0.5%
    Schuylkill County 619 0.5%
    Northumberland County 569 0.4%
    Fayette County 560 0.4%
    Crawford County 540 0.4%
    Clinton County 525 0.4%
    Mercer County 517 0.4%
    Lawrence County 466 0.3%
    Union County 421 0.3%
    Tioga County 413 0.3%
    Fulton County 382 0.3%
    Snyder County 362 0.3%
    Potter County 356 0.3%
    Cameron County 347 0.3%
    Somerset County 342 0.3%
    Warren County 342 0.3%
    Juniata County 288 0.2%
    Montour County 261 0.2%
    Greene County 161 0.1%
    Forest County 149 0.1%
    Sullivan County 99 0.1%
    Unknown County 12,392 9.2%

    "Unknown County" counts cases the CDC confirmed in Pennsylvania without a county of residence. They are included in the state total but not on the map.

    Data Sources

    All Lyme disease prevalence data sourced from the Centers for Disease Control and Prevention's surveillance data. Cases are counted by the patient's county of residence, which may not be where the tick bite occurred.

    TickCheck

    Connect with TickCheck on Facebook and Instagram for the latest tick news and tips.

    Facebook Instagram

    Did you just find a tick on yourself or a loved one? TickCheck can test your tick and determine whether it carries the bacteria that transmit Lyme disease and other tick-borne infections.

    Test My Tick Now