As tick season ramps up across the Northeast in spring 2026, Rhode Island holds an unwelcome distinction: the highest reported Lyme disease incidence rate of any U.S. state. According to data from the Rhode Island Department of Health’s tickborne disease dashboard, the state recorded 2,563 confirmed Lyme disease cases during the 2024 reporting year. For a state with roughly one million residents, that translates to 233.6 cases per 100,000 people, a rate visualized by Statista and far above the national average.
But that number comes with an important caveat. A 2022 change in how Lyme disease cases are counted nationally has reshaped the data in ways that complicate state-to-state comparisons and can make the raw figures look more alarming than the underlying biology may warrant.
The dashboard itself notes that case counts “should be interpreted with caution” due to changes in surveillance methodology, and that year-over-year comparisons across the 2022 threshold are not straightforward. That warning is easy to miss when the topline number circulates without context.
What the numbers actually show
Rhode Island’s 2,563 cases in 2024 follow a pattern that began in 2022, when the state logged 2,324 cases. A state health department press release from that year confirmed the jump and attributed it directly to a national change in case reporting, not to a sudden explosion in tick populations.
The change came from the Council of State and Territorial Epidemiologists (CSTE), which updated the national surveillance case definition for Lyme disease in 2022. Under the old rules, every state needed both laboratory evidence and clinical confirmation, such as a documented tick bite or characteristic symptoms, before a case was officially counted. The revised definition created a two-track system. States designated as high-incidence jurisdictions, including Rhode Island, can now count a case based on a positive lab test alone. States with lower baseline rates still need both lab results and clinical criteria.
The practical effect is significant. Positive lab results that previously would have been filtered out during clinical review now count as confirmed cases in high-incidence states. Rhode Island’s health department has been transparent about this, flagging the 2022 increase on its data page as a consequence of the CSTE revision. Nationally, Lyme disease cases rose by roughly 70 percent in 2022, a spike that the Associated Press, reporting on CDC surveillance data, attributed to the methodology shift rather than a biological surge.
A peer-reviewed study published in Zoonoses and Public Health by CDC-affiliated researchers examined the quantitative impact of switching to laboratory-based surveillance in high-incidence states. The analysis found that the new reporting method can substantially change the number of reportable cases, confirming that surveillance definitions are not neutral. They shape the apparent size of an outbreak by determining which positive results get counted and which get excluded.
Why the ranking is hard to interpret
Rhode Island’s top spot in the Statista data is real in a statistical sense, but the picture is muddier than a simple leaderboard suggests.
No primary source in the available evidence provides current data on blacklegged tick population densities or infection rates in Rhode Island ticks. Without entomological field surveys, the surveillance numbers alone cannot separate a state where more people are bitten by infected ticks from a state where the reporting pipeline simply captures more positive lab tests.
The asymmetry in the two-track system also skews comparisons. States outside the high-incidence designation must still apply stricter clinical criteria before a lab-positive test is counted, which can suppress their official rates. If clinicians in lower-incidence states are also less likely to order Lyme serology for patients with nonspecific symptoms, their case counts may reflect gaps in testing rather than genuinely lower exposure. Rhode Island, by contrast, has a well-established testing and reporting infrastructure built over decades of dealing with Lyme disease.
There are also open questions about how clinicians and laboratories have adapted since 2022. If Rhode Island providers have lowered their threshold for ordering Lyme tests, or if labs have changed their reporting practices in response to the high-incidence designation, case counts could rise without a proportional change in actual infections. The available sources do not document whether these behavioral shifts have occurred.
Even the baseline years used for comparison carry uncertainty. The CDC’s own Lyme surveillance data includes COVID-era incompleteness caveats for some jurisdictions, meaning that if reporting gaps disproportionately affected regions outside New England, Rhode Island’s apparent lead could partly reflect better data continuity rather than uniquely intense risk.
Where in Rhode Island the risk concentrates
Rhode Island’s small size can make it tempting to treat the entire state as a single risk zone, but tick exposure is not evenly distributed. Washington County, which encompasses the southern coastal towns of South Kingstown, Charlestown, and Westerly, has historically reported some of the highest Lyme disease case rates in the state. The mix of dense woodland, tall grass, and stone-wall edges that characterize the area creates ideal habitat for blacklegged ticks and the white-footed mice that serve as primary reservoirs for Borrelia burgdorferi.
Popular outdoor areas such as the Arcadia Management Area in Exeter and West Greenwich, the Trustom Pond National Wildlife Refuge in South Kingstown, and the network of trails in Lincoln Woods State Park in the northern part of the state all place visitors in tick-friendly environments. Block Island, a seasonal tourist destination roughly 13 miles off the southern coast, has long been recognized as a Lyme disease hotspot, with studies dating back decades documenting high tick infection rates on the island.
The state’s tickborne disease dashboard does not break down 2024 case counts by municipality or county in its public-facing display, which limits the ability to pinpoint exactly where transmission is most intense in the most recent data. Residents and visitors should treat any wooded, brushy, or grassy area in the state as potential tick habitat, particularly from April through July when nymphal ticks, the life stage most responsible for transmitting Lyme disease to humans, are most active.
What Rhode Islanders should know this spring
Regardless of how much the reporting methodology inflates the exact incidence rate, the volume of positive lab tests confirms that Borrelia burgdorferi is widespread among ticks in Rhode Island. The state’s high-incidence designation is not a statistical accident. People who live in, work in, or visit the state during tick season, which typically runs from April through October and peaks in late spring and early summer, face meaningful exposure risk.
Standard prevention measures remain the most effective defense:
- Use insect repellent containing DEET on skin or permethrin on clothing and gear.
- Wear long sleeves and pants when walking through wooded, brushy, or grassy areas.
- Perform thorough tick checks on yourself, children, and pets after spending time outdoors.
- Remove attached ticks promptly with fine-tipped tweezers, grasping as close to the skin as possible and pulling straight out.
- Shower within two hours of coming indoors, which can help wash off unattached ticks.
Anyone who develops a bull’s-eye rash, unexplained fever, fatigue, or joint pain after a possible tick bite should seek medical evaluation quickly. Early antibiotic treatment is highly effective at preventing the long-term complications associated with Lyme disease, including chronic joint inflammation and neurological symptoms.
How reporting mechanics and real risk overlap in Rhode Island
Rhode Island’s position at the top of the Lyme disease incidence chart reflects a genuine signal of substantial local transmission layered on top of a significant reporting effect. The 2022 change in how cases are counted means the raw numbers are not directly comparable to pre-2022 data, and the two-track surveillance system makes state-to-state rankings less straightforward than they appear.
None of that changes the core reality for anyone spending time outdoors in Rhode Island this spring: the ticks are there, the bacteria they carry are there, and the risk of Lyme disease is among the highest in the country by any reasonable measure. Understanding the data caveats matters for policymakers and epidemiologists. For everyone else, the priority is simpler: check for ticks, and do it every time.
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*This article was researched with the help of AI, with human editors creating the final content.
