Special Report

The Worst States For Lyme Disease

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16. Massachusetts
> Avg. new Lyme disease cases per year: 1.7 confirmed cases per 100,000 people
> Total cases in 2019: 7 (6 confirmed, 1 probable)
> Worst year in last decade: 2013; 57.0 confirmed cases per 100,000 people
> Physically active adults: 80.0% (13th highest)
> Uninsured rate: 3.0% (the lowest)

With more than 10 confirmed cases for every 100,000 people from 2010 to 2015, Massachusetts is one of 16 high-incidence states, including Washington D.C., identified by the CDC. However, Lyme disease infection rates have declined precipitously in the state over the last few years. The average infection rate between 2017 to 2019 was just 1.7 per 100,000 people, well below the decade high of 57.0 per 100,000 in 2013. There were a total of only six confirmed cases of the disease in the state in 2019.

Public health officials in Massachusetts dispute the figures reported by the CDC, claiming that the actual number of cases has not declined by over 90%, but rather remained steady in recent years. The disparity may be linked to the CDC’s standard of requiring both a clinical diagnosis and a positive lab test for a case of the disease to be counted — a standard state officials claim is overly burdensome.

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15. District of Columbia
> Avg. new Lyme disease cases per year: 8.4 confirmed cases per 100,000 people
> Total cases in 2019: 100 (57 confirmed, 43 probable)
> Worst year in last decade: 2015; 11.6 confirmed cases per 100,000 people
> Physically active adults: 82.6% (5th highest)
> Uninsured rate: 3.5% (2nd lowest)

There are an average of 8.4 confirmed cases of Lyme disease in the District of Columbia annually — a higher infection rate than in all but 14 states. The worst year for the disease over the last decade was 2015, when there were 11.6 confirmed cases per 100,000 people.

Unlike many states with high Lyme infection rates, D.C. is an urban area with relatively little green space. Still, the spring and summer humidity in the area provides ideal conditions for ticks, which can still be found in backyards and parks in the city and pass the disease from mice, rather than deer, as is the case in the Northeastern U.S.

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14. Virginia
> Avg. new Lyme disease cases per year: 10.1 confirmed cases per 100,000 people
> Total cases in 2019: 1,199 (788 confirmed, 411 probable)
> Worst year in last decade: 2015; 13.1 confirmed cases per 100,000 people
> Physically active adults: 77.8% (24th highest)
> Uninsured rate: 7.9% (25th lowest)

Virginia is one of several states in the mid-Atlantic region with a relatively high incidence rate of Lyme disease. There are an average of 10.1 cases in the state for every 100,000 people annually, 14th highest among states. Peak transmission in the state occurs in May and June, and residents who spend time in heavily wooded areas are at increased risk.

The state’s infection rate rose slightly in 2019 to 9.2 cases per 100,000 people from 8.7 the previous year. Still, infections remain below the decade high of 13.1 per 100,000 recorded in 2015.

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13. New York
> Avg. new Lyme disease cases per year: 14.9 confirmed cases per 100,000 people
> Total cases in 2019: 4,243 (2,847 confirmed, 1,396 probable)
> Worst year in last decade: 2013; 17.9 confirmed cases per 100,000 people
> Physically active adults: 76.6% (19th lowest)
> Uninsured rate: 5.2% (8th lowest)

The average incidence rate of Lyme disease in New York state of 14.9 cases per 100,000 people annually is the 13th highest among states. There were 2,847 confirmed cases in 2019 and another 1,396 probable cases that were not factored into the infection rate.

While much of New York is forested and rural — areas that many associate with higher risk of Lyme disease — those in urban parts of the state still face some risk. Over 40% of the state’s population live in New York City, where parks and backyards can be an ideal habitat for disease-carrying ticks. There have been as many as 1,000 confirmed cases in a single year in New York City.

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12. Maryland
> Avg. new Lyme disease cases per year: 15.9 confirmed cases per 100,000 people
> Total cases in 2019: 1,417 (804 confirmed, 613 probable)
> Worst year in last decade: 2016; 21.2 confirmed cases per 100,000 people
> Physically active adults: 78.1% (21st highest)
> Uninsured rate: 6.0% (13th lowest)

As is the case across the United States, Lyme disease is the most common tick-borne disease in Maryland. There are an average of 15.9 confirmed cases of Lyme disease in the state annually for every 100,000 people, the 12th highest rate among states.

Mid-Atlantic states such as Maryland tend to have warm and humid spring and summer seasons, which are ideal conditions for blacklegged ticks. However, cases of Lyme disease appear to be becoming increasingly less common across Maryland. The incidence rate of Lyme has fallen each year since hitting a decade peak of 21.2 cases per 100,000 people in 2016. There were only 13.3 confirmed cases per 100,000 people in the state in 2019.