Lyme disease is a debilitating, sometimes deadly infection, transmitted to humans through bites of blacklegged ticks, commonly known as deer ticks. Lyme disease typically induces flu-like symptoms, including sore joints, and headaches. According to Centers for Disease Control and Prevention estimates, 300,000 Americans are infected with Lyme disease each year.
In the last 10 years, Lyme disease has been diagnosed in every state except for Hawaii. However, 96% of all confirmed cases of Lyme were isolated to only 14 states in 2014. 24/7 Wall St. reviewed CDC data on confirmed cases of the disease to determine the worst states in the country for Lyme disease. In Maine, there were 87.9 confirmed cases of Lyme disease for every 100,000 state residents, the most of any state and more than 11 times the nationwide diagnosis rate of 7.9 cases per 100,000 Americans.
In an interview with 24/7 Wall St., Candice Hoffmann, a spokesperson with the CDC, explained that what is now known as Lyme disease “was described in Europe in the early 20th century,” but not identified in the United States until the 1970s. The first known cases in the U.S. were in Lyme, Connecticut when children experienced flu-like symptoms in the summer months. Since then, the disease has been widely studied and diagnosed in nearly every state.
According to Hoffmann, various types of blacklegged ticks that carry the disease are found in humid areas. In certain parts of the country, such as the Midwest and Northeast, “ticks feed upon small mammals and birds that have the Lyme disease bacteria in their blood” and then “spread the bacteria to humans.”
Given the geographic location of the disease’s namesake, it is perhaps not surprising that Lyme disease cases are most common in New England. All six of the New England states are among the seven worst states in the country for Lyme disease. Other states with the highest incidences of Lyme disease are either Mid-Atlantic or Midwestern states.
Lyme disease is contracted from blacklegged ticks that typically live in wooded areas. “Highly urbanized settings generally are not considered to present high risk of Lyme disease because of the lack of suitable tick habitat,” said Hoffman. By contrast, Lyme-carrying ticks are relatively common in rural areas. As a result, those who spend time in these areas are at greater risk of infection. Maine and Vermont, the two states with the highest infection rates, are also home to the largest share of residents living in rural areas.
However, not every state with the highest Lyme disease incidence are especially rural. People are also likely to come into contact with infected ticks in suburban environments “whether in backyards, public parks, or hiking trails,” Hoffmann said.
The incidence of Lyme disease is on the rise in the United States. Hoffmann noted that due largely to climate change, the geographic regions suitable to ticks are getting larger. While the factors involved are very complex, Hoffmann added this will likely continue in future decades. The diagnosis has rate has gone up by 8% across the U.S. in the last 10 years.
Diagnoses of the disease have spiked even more dramatically in certain states. However, according to Hoffmann, the increases may be due largely to reporting methods. “Surveillance data are subject to each state’s abilities to capture and classify cases, which are dependent upon budget and personnel and varies not only between states, but also from year to year within a given state,” Hoffmann said. Some of these especially dramatic increases may not actually represent a true change in disease incidence.
While the disease is widespread and public awareness is increasing, there is much to be learned about Lyme disease. People are often misdiagnosed as symptoms can vary from patient to patient. For example, while many associate a bull’s eye-shaped rash with the disease, such a rash does not always appear. Even blood tests that check for the presence of antibodies are not always an accurate diagnostic tool. While the disease is often curable with a regimen of antibiotics, in some patients, symptoms can linger for months and even years.
In order to determine the 12 worst states for Lyme disease, 24/7 Wall St. reviewed CDC data on the number of confirmed cases in each state for every 100,000 residents in 2014. States were ranked in order from the lowest incidences to the highest, and only those states with a confirmed infection rate more than double the national rate were ranked. We also reviewed the total number of confirmed cases, along with the incidence rate, for each of the previous 10 years. The number of probable cases in 2014 also came from the CDC. Supplemental data, including the percent of physically active adults, percentage of a population with access to places for physical activity, and the percentage of the population living in rural areas came from County Health Rankings & Roadmaps, a Robert Wood Johnson Foundation and University of Wisconsin Population Health Institute joint program.
These are the worst states for Lyme disease.
Maryland is one of several Mid-Atlantic states where Lyme disease is more than twice as common as it is nationwide. There were 16.0 confirmed cases of the disease in 2014 for every 100,000 residents, far more than the national incidence of 7.9 cases per 100,000 people. While Lyme disease is still relatively common in Maryland, 2014 marked the second lowest rate in the last 10 years. Infections per capita peaked in the state in 2007, when there were 45.8 confirmed infections for every 100,000 state residents.
Earlier this year, Maryland Governor Larry Hogan signed the state’s first bill related to Lyme disease into law. The new law requires that doctors provide a written note to patients explaining that negative tests results do not necessarily mean the patient is free of the disease. The law illustrates the ambiguities surrounding Lyme disease testing and diagnosis.
>Incidence of Lyme disease: 16.4 (per 100,000 residents)
>Confirmed cases: 896 (10th highest)
>Pct. population rural: 26.7%
>Pct. adults physically active: 80.5% (8th highest)
There were 896 confirmed cases of Lyme disease and another 520 likely cases in Minnesota in 2014 alone. Counties at the highest risk of Lyme disease are located in the northern half of the state, and along the border with Wisconsin, a state with a similar Lyme incidence rate. The disease is contracted from ticks that thrive in the region’s many forested areas. More than a quarter of the state’s population lives in rural areas, and 80.5% of Minnesota adults lead physically active lives. While remaining active can be an important component of a healthy lifestyle, it can also put individuals at a greater risk of contracting Lyme disease, specifically in wooded areas.
Last year, a Twin Cities man died after his heart suddenly stopped due to Lyme carditis, a rare complication that can be triggered by Lyme disease.
>Incidence of Lyme disease: 17.2 (per 100,000 residents)
>Confirmed cases: 991 (7th highest)
>Pct. population rural: 29.8%
>Pct. adults physically active: 78.3% (17th highest)
Wisconsin is the worst state in the Midwest for Lyme disease. There were 17.2 confirmed cases of the disease for every 100,000 state residents in 2014, well more than double the nationwide Lyme disease infection rate. Incidence of the disease peaks in summer months — and 2014 was no different in Wisconsin. More than half of all confirmed cases that year were reported in June and July.
Though Lyme is more common in Wisconsin than in much of the country, the 2014 incidence rate marked a 10-year low in the state. There were 34.8% fewer confirmed cases per capita in 2014 than there were a decade prior. The incidence rate in Wisconsin peaked in 2010, when there were 44 confirmed cases for every 100,000 state residents.
Earlier this year, Assembly Bill 768, which would have implemented a standard set of rules related to diagnosing and treating Lyme disease, failed to pass in the state senate.
9. New Jersey
>Incidence of Lyme disease: 29.0 (per 100,000 residents)
>Confirmed cases: 2,589 (4th highest)
>Pct. population rural: 5.3%
>Pct. adults physically active: 75.9% (22nd lowest)
There were 2,589 confirmed cases of Lyme disease and another 697 probable cases in New Jersey in 2014. Not counting the unconfirmed cases, the incidence rate of 29 cases per 100,000 state residents is the ninth highest of any state in the country. Though only about 5% of New Jersey residents live in rural areas, nearly 95% of people in the Garden State have easy access to areas for physical activity, the largest share of any state in the country. Hoffmann explained that even suburban backyards, parks, and public spaces can be suitable habitats for Lyme-carrying ticks.
As was the case nationwide, the Lyme disease infection rate peaked in New Jersey in 2009. That year, there were 4,598 confirmed cases, or 52.8 incidents for every 100,000 state residents.
>Incidence of Lyme disease: 36.4 (per 100,000 residents)
>Confirmed cases: 341 (14th highest)
>Pct. population rural: 16.7%
>Pct. adults physically active: 75.2% (16th lowest)
Lyme disease was more common in Delaware than in any other state during five of the last 10 years. However, the diagnosis rate has fallen recently in the state. There were 36.4 confirmed cases of Lyme disease for every 100,000 state residents in 2014, a 50% decline from 2010.
State lawmakers are taking proactive measures to address the disease. The state legislature recently passed two bills based on recommendations from a newly-created Lyme Disease Prevention Task Force. House Bill 290 is aimed at reducing the number of disease-carrying ticks in the state, and House Bill 291 is meant to ensure comprehensive, ongoing Lyme disease education for medical professionals in the state.
7. New Hampshire
>Incidence of Lyme disease: 46.9 (per 100,000 residents)
>Confirmed cases: 622 (11th highest)
>Pct. population rural: 39.7%
>Pct. adults physically active: 79.2% (13th highest)
There were 622 cases of Lyme disease in New Hampshire in 2014. The incidence of Lyme disease diagnosis can vary year to year depending on a number of conditions, including weather and awareness. While generally the disease is becoming more common in the United States, diagnosis rates in New Hampshire have improved in recent years. The number of incidents per capita in the state is down by roughly a quarter from five years ago.
The ticks that can transfer Lyme disease to humans are typically found in heavily wooded areas. In New Hampshire, 39.7% of the population lives in a rural area, one of the highest such shares of any state in the country.
>Incidence of Lyme disease: 47.8 (per 100,000 residents)
>Confirmed cases: 1,719 (5th highest)
>Pct. population rural: 12.0%
>Pct. adults physically active: 78.2% (18th highest)
Lyme disease gets its name from Lyme, Connecticut, a small town along the eastern shore of Connecticut River, just north of Long Island Sound. The disease was discovered there in the mid-1970s, when children were being diagnosed with juvenile rheumatoid arthritis at the height of tick season. Today, Lyme disease is far more common in Connecticut than in much of the country, with 47.8 diagnoses for every 100,000 state residents in 2014.
Lyme disease is typically contracted in wooded areas, and though a relatively small share of Connecticut residents live in rural areas, there are still many opportunities for individuals to be exposed to black-legged ticks. In Connecticut, 94.4% of state residents have adequate access to areas for physical activity, the second highest share of any state in the country. These areas include parks, which are often heavily wooded.
>Incidence of Lyme disease: 50.6 (per 100,000 residents)
>Confirmed cases: 6,470 (the highest)
>Pct. population rural: 21.3%
>Pct. adults physically active: 76.0% (24th lowest)
Pennsylvania had the highest number of confirmed cases of Lyme disease in 2014. There were 50.6 cases of the disease for every 100,000 state residents, more than in all but four other states. As was the case in many other states, 2014 marked a 10-year high for Lyme disease in Pennsylvania. In fact, the 2014 infection rate in the Keystone State is nearly double the rate from just five years ago.
In 2014, the state created a task force to recommend policy changes to increase education, awareness, prevention, and surveillance of Lyme disease. The task force submitted more than a dozen recommendations in 2015, including a multimedia public awareness campaign designed to target high risk groups such as school-age children and older adults.
4. Rhode Island
>Incidence of Lyme disease: 54.0 (per 100,000 residents)
>Confirmed cases: 570 (12th highest)
>Pct. population rural: 9.3%
>Pct. adults physically active: 75.9% (22nd lowest)
There were only 3.6 Lyme disease diagnoses for every 100,000 Rhode Island residents in 2005. Since then, the incidence of Lyme disease in the state has shot up, and 2014’s rate was 15 times higher. This was by far the largest increase in the country. Some medical experts attribute the sharp increase to underreporting in years past. Still, current data suggest that Lyme disease is more common in Rhode Island than in all but three other states.
Perhaps due to the disease’s prevalence in the state, Rhode Island is home to a specialized treatment center. The Lifespan Lyme Disease Center opened at Newport Hospital in 2015 with the intended purpose of treating certain ongoing symptoms of Lyme disease that can continue long after the initial infection has been treated.
>Incidence of Lyme disease: 54.1 (per 100,000 residents)
>Confirmed cases: 3,646 (2nd highest)
>Pct. population rural: 8.0%
>Pct. adults physically active: 78.4% (16th highest)
In the last 10 years, the incidence of Lyme in Massachusetts peaked in 2009, when there were 61 cases for every 100,000 residents. Still, the diagnosis rate of 54.1 incidents per 100,000 people in 2014 is 49% higher than it was 10 years prior. While the CDC confirmed 3,646 cases in the state in 2014, there were also an additional 1,658 probable cases that could not be confirmed.
According to findings of a 2013 report compiled by a team of experts and political leaders, including the Commissioner of the Department of Public Health, much more needs to be done to address Lyme disease in the Bay State — and across the nation. The report cited antiquated diagnosis methods and insufficient treatment protocols as major impediments to better outcomes. According to the report, Lyme disease costs Massachusetts millions of dollars a year, both in employee absences and medical costs.
>Incidence of Lyme disease: 70.5 (per 100,000 residents)
>Confirmed cases: 442 (13th highest)
>Pct. population rural: 61.1%
>Pct. adults physically active: 80.9% (7th highest)
Lyme disease is more common in Vermont than in any other state in the country other than Maine. There were 70.5 incidents of Lyme disease in Vermont for every 100,000 residents in 2014. While the high incidence of Lyme disease in Vermont is largely attributable to geography, the active, outdoor lifestyles of state residents also increases their risk of exposure. Nearly 81% of adults in the state are regularly physically active, one of the highest shares of any state in the country. Additionally, Lyme disease is typically contracted in wooded areas, and 61.1% of people Vermont live in rural areas, the second largest share in the country.
>Incidence of Lyme disease: 87.9 (per 100,000 residents)
>Confirmed cases: 1,169 (6th highest)
>Pct. population rural: 61.3%
>Pct. adults physically active: 78.6% (15th highest)
The Lyme disease incidence rate of 87.9 diagnoses per 100,000 Maine residents is the highest it has been in the state in the last decade. Lyme disease is more than twice as common as it was just five years ago. It is perhaps not surprising that Maine is also the most rural state in the country, with 61.3% of the population residing in rural areas.
With the highest incidence rate in the country, Maine is doing more than most states to understand and combat Lyme disease. Last year, the University of Maine approved a $9 million laboratory dedicated to studying diseases transmitted by pests, including Lyme. In addition, the state CDC, in partnership with the Department of Health and Human Services and the Division of Infectious Disease, has published a report each year since 2009 to provide recommendations to lawmakers on policy regarding Lyme disease.