Cumulative tick-borne disease load

Top-100 counties

The 100 U.S. counties with the highest cumulative CDC-reported tick-borne disease cases. We frame this as epidemiology, not stigma — high-load counties are places with higher tick density and reporting completeness, not worse places to live.

Hotspots

100 counties
RankCountyStateTotal casesDiseasesLatest year
01Dutchess CountyNY15,00882023
02Chester CountyPA14,11282023
03Suffolk CountyNY13,36382023
04Middlesex CountyMA11,38582023
05Morris CountyNJ10,96582023
06Bucks CountyPA10,82282023
07Montgomery CountyPA10,45782023
08Fairfield CountyCT10,42982023
09Orange CountyNY9,25582023
10Plymouth CountyMA9,12282023
11Columbia CountyNY8,87682023
12Monmouth CountyNJ8,64282023
13Hunterdon CountyNJ8,52382023
14New York CountyNY7,97982023
15Ulster CountyNY7,96582023
16Westchester CountyNY7,84482023
17Worcester CountyMA7,77182023
18Bristol CountyMA7,68182023
19New London CountyCT7,66682023
20Sussex CountyNJ7,41682023
21York CountyPA7,34282023
22Rockingham CountyNH7,18982023
23New Haven CountyCT6,93982023
24New Castle CountyDE6,87282023
25Norfolk CountyMA6,84982023
26Rensselaer CountyNY6,79182023
27Providence CountyRI6,75882023
28Washington CountyRI6,57482023
29Hillsborough CountyNH6,33182023
30Kings CountyNY6,12982023
31Albany CountyNY5,94982023
32Essex CountyMA5,81882023
33Ocean CountyNJ5,64782023
34Cumberland CountyME5,62082023
35Butler CountyPA5,58082023
36Berks CountyPA5,52182023
37Warren CountyNJ5,47582023
38Litchfield CountyCT5,29382023
39Bergen CountyNJ5,03282023
40York CountyME4,90682023
41Barnstable CountyMA4,78882023
42Allegheny CountyPA4,72382023
43Somerset CountyNJ4,71182023
44Lancaster CountyPA4,68882023
45Burlington CountyNJ4,67182023
46Hennepin CountyMN4,66082023
47Hartford CountyCT4,60082023
48Delaware CountyPA4,55282023
49Westmoreland CountyPA4,53682023
50Mercer CountyNJ4,42482023
51Rockland CountyNY4,18182023
52Windham CountyCT4,16182023
53Montgomery CountyMD4,14882023
54Putnam CountyNY4,11582023
55Middlesex CountyNJ4,03582023
56Philadelphia CountyPA4,02482023
57Tolland CountyCT3,99882023
58Saratoga CountyNY3,85482023
59Clearfield CountyPA3,78482023
60Greene CountyNY3,76282023
61Baltimore CountyMD3,72382023
62Loudoun CountyVA3,61082023
63Howard CountyMD3,54482023
64Lehigh CountyPA3,53682023
65Passaic CountyNJ3,48882023
66Kennebec CountyME3,26282023
67Fairfax CountyVA3,20482023
68Northampton CountyPA3,16182023
69Middlesex CountyCT3,14482023
70Essex CountyNJ3,07082023
71Anne Arundel CountyMD2,98082023
72Kent CountyRI2,97582023
73Centre CountyPA2,92182023
74Dauphin CountyPA2,85982023
75Strafford CountyNH2,84582023
76Dane CountyWI2,84582023
77Berkshire CountyMA2,81282023
78Ramsey CountyMN2,79582023
79Carroll CountyMD2,78382023
80Knox CountyME2,74782023
81Washington CountyNY2,74182023
82Atlantic CountyNJ2,69782023
83Hampden CountyMA2,68982023
84Gloucester CountyNJ2,67382023
85Bennington CountyVT2,66982023
86Anoka CountyMN2,65282023
87Frederick CountyMD2,64182023
88Queens CountyNY2,61782023
89Harford CountyMD2,61282023
90Cumberland CountyPA2,60582023
91Merrimack CountyNH2,57682023
92Hancock CountyME2,51882023
93Nassau CountyNY2,50282023
94Jefferson CountyPA2,49182023
95Washington CountyMN2,48582023
96Crow Wing CountyMN2,48182023
97Marathon CountyWI2,42082023
98Rutland CountyVT2,40382023
99Armstrong CountyPA2,32082023
100Windsor CountyVT2,28282023