Tickpedia
Tick-borne illness

Lyme disease

Lyme disease is a bacterial infection (Borrelia burgdorferi) spread by black-legged ticks and the most common tick-borne illness in the US.

Cases · 748,103Carried by 3 ticksPeak · JulyView risk map →
Continental risk map
Where Lyme disease hits hardest
H3 hexagon heatmap of 748,103 reported cases across 51 states.
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State-by-state cases

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Alaska — 143 casesAKMaine — 25,686 casesMEVermont — 11,360 casesVTNew Hampshire — 21,129 casesNHWashington — 462 casesWAIdaho — 198 casesIDMontana — 132 casesMTNorth Dakota — 465 casesNDMinnesota — 34,828 casesMNWisconsin — 50,801 casesWIMichigan — 5,413 casesMINew York — 132,411 casesNYMassachusetts — 59,509 casesMAOregon — 905 casesORNevada — 203 casesNVWyoming — 47 casesWYSouth Dakota — 113 casesSDIowa — 3,875 casesIAIllinois — 4,903 casesILIndiana — 2,102 casesINOhio — 5,057 casesOHPennsylvania — 147,886 casesPANew Jersey — 86,774 casesNJConnecticut — 43,356 casesCTCalifornia — 2,218 casesCAUtah — 232 casesUTColorado — 65 casesCONebraska — 192 casesNEMissouri — 331 casesMOKentucky — 489 casesKYWest Virginia — 11,590 casesWVVirginia — 20,225 casesVAMaryland — 33,787 casesMDDelaware — 10,803 casesDERhode Island — 17,265 casesRIArizona — 244 casesAZNew Mexico — 75 casesNMKansas — 388 casesKSArkansas — 67 casesARTennessee — 641 casesTNNorth Carolina — 3,826 casesNCSouth Carolina — 783 casesSCDistrict of Columbia — 1,371 casesDCHawaii — no CDC-reported casesHIOklahoma — 21 casesOKLouisiana — 100 casesLAMississippi — 77 casesMSAlabama — 550 casesALGeorgia — 381 casesGATexas — 1,753 casesTXFlorida — 2,871 casesFLCASES · PER STATE
none
most cases

748,103 reported cases across 51 states.

Top 8 states
#NameCases
1Pennsylvania147,886
2New York132,411
3New Jersey86,774
4Massachusetts59,509
5Wisconsin50,801
6Connecticut43,356
7Minnesota34,828
8Maryland33,787

Seasonality

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JFMAMJJASOND

Cases peak in July — about 25,214 cases reported.

MonthCases
Jan2,401
Feb2,071
Mar2,770
Apr3,905
May9,088
Jun24,356
Jul25,214
Aug11,424
Sep6,504
Oct5,790
Nov3,487
Dec1,615

Year-over-year

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85,44164,08142,72121,360020012004200720102013201620192022REPORTED CASES · PER YEAR

Ticks that carry it

3 known
TickScientific nameOne-liner
Blacklegged tickIxodes scapularisThe black-legged tick is the primary US vector of Lyme disease, established across the Northeast, Upper Midwest, and Mid-Atlantic.
Castor bean tickIxodes ricinusThe castor bean tick is the principal European vector of Lyme borreliosis and tick-borne encephalitis, ranging from Britain to the Caspian.
Western blacklegged tickIxodes pacificusThe western black-legged tick carries Lyme disease and anaplasmosis along the Pacific Coast from California to British Columbia.

Pathogens that cause it

2 known
PathogenScientific nameOne-liner
Borrelia burgdorferiBorrelia burgdorferi sensu strictoSpirochete that causes Lyme disease in the eastern US (carried by Ixodes scapularis) and on the west coast (carried by Ixodes pacificus).
Borrelia mayoniiBorrelia mayoniiLyme-disease-causing spirochete first identified in 2013 in upper-midwest deer ticks; produces a distinctive diffuse rash and high spirochetal load.

Wild facts

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