Two views of every state: our risk level for the season, and what CDC's own case counts say about whether Lyme is spreading. Tap a state for both. This past winter was the second-warmest on record nationally (NOAA), though the Northeast, where most Lyme occurs, ran cooler than average.
Is Lyme getting worse where you live? In 12 states and D.C., CDC's own numbers say yes. Comparing 2012–14 with 2017–19 (before CDC's 2022 counting change), reported Lyme rose fastest in West Virginia (6.8 → 40.8 cases per 100,000 people), Ohio (0.8 → 2.9) and Michigan (1.3 → 3.2). Of the 16 jurisdictions CDC counts as high-incidence, 7 rose, 7 held about steady, 1 fell (Connecticut) and 1 has no comparable data (Massachusetts).
CDC Lyme surveillance data 2012–2023 · rates from US Census Bureau estimates · How we calculate itTap or click a state to see its risk level and Lyme numbers.
What the risk levels mean
Our editorial assessment for the season. Severe covers the 16 jurisdictions CDC classifies as high-incidence for Lyme disease. High, Moderate and Low reflect where CDC maps disease-carrying ticks (blacklegged, lone star, American dog tick) as established and which tick-borne diseases are reported there.
Ticks present but disease incidence is low. Standard precautions on trails.
10 states Alaska, Arizona, Hawaii, Idaho, Montana, Nevada, New Mexico, North Dakota, Utah and Wyoming.
Lone star and dog ticks active spring through fall. Repellent advised for grass and woods.
15 states Alabama, California, Colorado, Florida, Georgia, Kansas, Louisiana, Mississippi, Nebraska, Oklahoma, Oregon, South Carolina, South Dakota, Texas and Washington.
Established blacklegged (deer) tick population. Lyme and anaplasmosis reported. Treat clothing with permethrin.
10 states Arkansas, Illinois, Indiana, Iowa, Kentucky, Michigan, Missouri, North Carolina, Ohio and Tennessee.
Among the highest Lyme incidence in the nation. Peak nymph activity May–July: permethrin on clothing + 12-hr skin repellent, daily tick checks.
15 states + D.C. Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia, Wisconsin and Washington, D.C.
Reported cases per 100,000 people, comparing 2012–14 with 2017–19: both before CDC's 2022 counting change, which makes later years incomparable. ● marks the 16 long-established jurisdictions CDC counts as high-incidence.
| State | 2012–14 | 2017–19 | Change | ||
|---|---|---|---|---|---|
| More Lyme · 12 states and D.C. | |||||
| West Virginia ● | 6.8 | 40.8 | ×5.9 | ||
| Ohio | 0.8 | 2.9 | ×3.7 | ||
| Michigan | 1.3 | 3.2 | ×2.5 | ||
| Washington, D.C. ● | 5.7 | 12.5 | ×2.3 | ||
| North Carolina | 1.6 | 2.7 | ×1.8 | ||
| Rhode Island ● | 58.3 | 101.3 | ×1.7 | ||
| Pennsylvania ● | 47.7 | 81.0 | ×1.7 | ||
| Indiana | 1.5 | 2.4 | ×1.6 | ||
| Oregon | 1.1 | 1.7 | ×1.6 | ||
| Wisconsin ● | 29.1 | 40.5 | ×1.4 | ||
| Maine ● | 97.5 | 134.9 | ×1.4 | ||
| Iowa | 6.5 | 8.9 | ×1.4 | ||
| Vermont ● | 107.3 | 145.9 | ×1.4 | ||
| About the same · 8 states | |||||
| Illinois | 2.0 | 2.5 | ×1.2 | ||
| New Jersey ● | 40.0 | 47.7 | ×1.2 | ||
| New Hampshire ● | 97.0 | 111.2 | ×1.2 | ||
| New York ● | 19.3 | 22.2 | ×1.1 | ||
| Delaware ● | 57.6 | 61.1 | ×1.1 | ||
| Maryland ● | 23.7 | 25.9 | ×1.1 | ||
| Virginia ● | 15.2 | 15.7 | ×1.1 | ||
| Minnesota ● | 32.5 | 32.1 | ×1.0 | ||
| Less Lyme · 1 state | |||||
| Connecticut ● | 73.7 | 48.0 | ×0.7 | ||
Rate = reported cases per 100,000 people a year.
Too few cases for a trend (18 states): Alabama, Alaska, Arizona, California, Florida, Georgia, Idaho, Kansas, Kentucky, Montana, Nebraska, Nevada, North Dakota, South Carolina, Tennessee, Texas, Utah and Washington.
No reliable trend (10 states): Arkansas, Colorado, Louisiana, Mississippi, Missouri, New Mexico, Oklahoma, South Dakota and Wyoming, where CDC's public data has too few years with cases; Massachusetts, where a change in reporting makes the years incomparable (see below). Hawaii has no CDC Lyme data.
Download the data (CSV): every state and year with reported cases, rate per 100,000 and notes. Free to reuse with credit to TickWise (CC BY 4.0); the underlying CDC and Census data are public domain.
Yes in 12 states and D.C., by CDC's own numbers. Comparing 2012–14 with 2017–19, reported Lyme per person rose there, held about steady in 8 states and fell in Connecticut. The biggest increases: West Virginia (×5.9), Ohio (×3.7), Michigan (×2.5) and Washington, D.C. (×2.3). In the other 28 states cases are too few, or the data too patchy, for a trend. Reported numbers also depend on how hard each state looks for cases, so read a trend as a signal, not a precise measure of risk.
Mostly because of counting. From 2022, CDC's case definition lets high-incidence states report a case from a positive lab test alone, without the clinical follow-up needed before. New York, for example, reported 4,243 cases in 2019 and 22,173 in 2023. CDC says the new numbers can't be compared with earlier years, which is why our trend stops at 2019.
Per person, in 2023: Rhode Island (259.0 cases per 100,000 people), Vermont (223.1), Maine (209.8), West Virginia (183.2) and Massachusetts (137.3). In total cases, New York (22,173) and Pennsylvania (16,671) reported the most. These 2023 figures use CDC's new case definition, which counts far more cases in high-incidence states than before.
From CDC's public-use Lyme disease surveillance data (confirmed and probable cases by state of residence, 2012–2023), with US Census Bureau population estimates for the rates. You can download our state-by-year table as a CSV and reuse it with credit to TickWise (CC BY 4.0). The underlying CDC and Census data are public domain.
Permethrin on clothing plus a 12-hour skin repellent. The four picks from this year's testing →
Four steps, then what to watch for over the following thirty days →
Regional briefings so far: Maine and the South — which ticks, which months, which diseases. Travelling outside the US this year? Our sister site NoBites Abroad has bite-risk guides for Ireland, Greece, the Netherlands, Malaysia and Barbados.