Climate change predicted to cause increase in Lyme disease

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Cases of Lyme disease are expected to increase by 20 percent in 15 states

In recent years, cases of Lyme disease have been on the rise. The Centers for Disease Control and Prevention (CDC) reports that 96 percent of all cases come from just 14 states, primarily in the Northeast and Midwest.

Because Lyme disease is transmitted through infected ticks, environmental factors -- particularly changes in temperature -- that allow these insects to thrive are found to be the main reason why the infection is affecting more consumers.

Researchers from Carnegie Mellon University and the Mayo Clinic College of Medicine and Science recently conducted a study that explores the connection between rising temperatures and rising numbers of Lyme disease.

“Tick-borne diseases are an important public health concern and the incidence of these infections is increasing in the United States and worldwide,” said lead researcher Igor Dumic. “Lyme disease is a classic example of the link between environmental factors and the occurrence and spread of the disease.”

Effect of rising temperatures

Most cases of Lyme disease are transmitted through ticks known as nymphs -- they’re tiny, hard to see, and often lodge themselves in difficult places like the scalp or armpit. For a human to get infected, the tick must latch on for 36-48 hours.

Ticks feed during the warmer months, and the heat directly affects their life cycles and behaviors. The more heat, the longer they can stay alive and remain active -- and infect people with Lyme disease. The behaviors of ticks are so dependent on the environment that the Environmental Protection Agency (EPA) uses the number of cases of Lyme disease as an indication of climate change.

The researchers analyzed environmental changes and the increasing number of Lyme disease cases in the fifteen states that report the highest numbers of the infection: Connecticut, Delaware, Maine, Maryland, Massachusetts, Minnesota, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont, Virginia, West Virginia, and Wisconsin.

Using data from both the CDC and the National Oceanic and Atmospheric Administration, the researchers predict that by mid-century, if the temperature continues to rise at its current rate, Lyme disease will affect 8.6 more people per 100,000 each year. That’s over 20 percent more than the current numbers.

“A sizable increase in the incidence of cases of Lyme disease in the United States due to climate change is imminent,” said researcher Edson Severnini. “Our findings should alert clinicians, public health professionals, and policymakers, as well as the general public.”

Lyme disease is growing

While climate change is just one aspect, Lyme disease is affecting more people than ever before.

Earlier this year, the CDC warned consumers that Lyme disease is on the rise and affecting more than 10 times as many people as previously expected.

“Each year, more than 30,000 cases of Lyme disease are reported nationwide, while studies suggest the actual number of people diagnosed with Lyme disease is more likely about 300,000,” the CDC reported.

Experts believe the increase comes from the disease spreading to previously un-reached parts of the country. According to a study conducted by Quest Diagnostics earlier this summer, Lyme disease has now been found in all 50 states.

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